xref: /openssh-portable/packet.c (revision cecee2d6)
1 /* $OpenBSD: packet.c,v 1.276 2018/07/09 21:03:30 markus Exp $ */
2 /*
3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5  *                    All rights reserved
6  * This file contains code implementing the packet protocol and communication
7  * with the other side.  This same code is used both on client and server side.
8  *
9  * As far as I am concerned, the code I have written for this software
10  * can be used freely for any purpose.  Any derived versions of this
11  * software must be clearly marked as such, and if the derived work is
12  * incompatible with the protocol description in the RFC file, it must be
13  * called by a name other than "ssh" or "Secure Shell".
14  *
15  *
16  * SSH2 packet format added by Markus Friedl.
17  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  * 1. Redistributions of source code must retain the above copyright
23  *    notice, this list of conditions and the following disclaimer.
24  * 2. Redistributions in binary form must reproduce the above copyright
25  *    notice, this list of conditions and the following disclaimer in the
26  *    documentation and/or other materials provided with the distribution.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 #include "includes.h"
41 
42 #include <sys/types.h>
43 #include "openbsd-compat/sys-queue.h"
44 #include <sys/socket.h>
45 #ifdef HAVE_SYS_TIME_H
46 # include <sys/time.h>
47 #endif
48 
49 #include <netinet/in.h>
50 #include <netinet/ip.h>
51 #include <arpa/inet.h>
52 
53 #include <errno.h>
54 #include <netdb.h>
55 #include <stdarg.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60 #include <limits.h>
61 #include <signal.h>
62 #include <time.h>
63 
64 #include <zlib.h>
65 
66 #include "xmalloc.h"
67 #include "crc32.h"
68 #include "compat.h"
69 #include "ssh2.h"
70 #include "cipher.h"
71 #include "sshkey.h"
72 #include "kex.h"
73 #include "digest.h"
74 #include "mac.h"
75 #include "log.h"
76 #include "canohost.h"
77 #include "misc.h"
78 #include "channels.h"
79 #include "ssh.h"
80 #include "packet.h"
81 #include "ssherr.h"
82 #include "sshbuf.h"
83 
84 #ifdef PACKET_DEBUG
85 #define DBG(x) x
86 #else
87 #define DBG(x)
88 #endif
89 
90 #define PACKET_MAX_SIZE (256 * 1024)
91 
92 struct packet_state {
93 	u_int32_t seqnr;
94 	u_int32_t packets;
95 	u_int64_t blocks;
96 	u_int64_t bytes;
97 };
98 
99 struct packet {
100 	TAILQ_ENTRY(packet) next;
101 	u_char type;
102 	struct sshbuf *payload;
103 };
104 
105 struct session_state {
106 	/*
107 	 * This variable contains the file descriptors used for
108 	 * communicating with the other side.  connection_in is used for
109 	 * reading; connection_out for writing.  These can be the same
110 	 * descriptor, in which case it is assumed to be a socket.
111 	 */
112 	int connection_in;
113 	int connection_out;
114 
115 	/* Protocol flags for the remote side. */
116 	u_int remote_protocol_flags;
117 
118 	/* Encryption context for receiving data.  Only used for decryption. */
119 	struct sshcipher_ctx *receive_context;
120 
121 	/* Encryption context for sending data.  Only used for encryption. */
122 	struct sshcipher_ctx *send_context;
123 
124 	/* Buffer for raw input data from the socket. */
125 	struct sshbuf *input;
126 
127 	/* Buffer for raw output data going to the socket. */
128 	struct sshbuf *output;
129 
130 	/* Buffer for the partial outgoing packet being constructed. */
131 	struct sshbuf *outgoing_packet;
132 
133 	/* Buffer for the incoming packet currently being processed. */
134 	struct sshbuf *incoming_packet;
135 
136 	/* Scratch buffer for packet compression/decompression. */
137 	struct sshbuf *compression_buffer;
138 
139 	/* Incoming/outgoing compression dictionaries */
140 	z_stream compression_in_stream;
141 	z_stream compression_out_stream;
142 	int compression_in_started;
143 	int compression_out_started;
144 	int compression_in_failures;
145 	int compression_out_failures;
146 
147 	/* default maximum packet size */
148 	u_int max_packet_size;
149 
150 	/* Flag indicating whether this module has been initialized. */
151 	int initialized;
152 
153 	/* Set to true if the connection is interactive. */
154 	int interactive_mode;
155 
156 	/* Set to true if we are the server side. */
157 	int server_side;
158 
159 	/* Set to true if we are authenticated. */
160 	int after_authentication;
161 
162 	int keep_alive_timeouts;
163 
164 	/* The maximum time that we will wait to send or receive a packet */
165 	int packet_timeout_ms;
166 
167 	/* Session key information for Encryption and MAC */
168 	struct newkeys *newkeys[MODE_MAX];
169 	struct packet_state p_read, p_send;
170 
171 	/* Volume-based rekeying */
172 	u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
173 
174 	/* Time-based rekeying */
175 	u_int32_t rekey_interval;	/* how often in seconds */
176 	time_t rekey_time;	/* time of last rekeying */
177 
178 	/* roundup current message to extra_pad bytes */
179 	u_char extra_pad;
180 
181 	/* XXX discard incoming data after MAC error */
182 	u_int packet_discard;
183 	size_t packet_discard_mac_already;
184 	struct sshmac *packet_discard_mac;
185 
186 	/* Used in packet_read_poll2() */
187 	u_int packlen;
188 
189 	/* Used in packet_send2 */
190 	int rekeying;
191 
192 	/* Used in ssh_packet_send_mux() */
193 	int mux;
194 
195 	/* Used in packet_set_interactive */
196 	int set_interactive_called;
197 
198 	/* Used in packet_set_maxsize */
199 	int set_maxsize_called;
200 
201 	/* One-off warning about weak ciphers */
202 	int cipher_warning_done;
203 
204 	/* Hook for fuzzing inbound packets */
205 	ssh_packet_hook_fn *hook_in;
206 	void *hook_in_ctx;
207 
208 	TAILQ_HEAD(, packet) outgoing;
209 };
210 
211 struct ssh *
212 ssh_alloc_session_state(void)
213 {
214 	struct ssh *ssh = NULL;
215 	struct session_state *state = NULL;
216 
217 	if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
218 	    (state = calloc(1, sizeof(*state))) == NULL ||
219 	    (state->input = sshbuf_new()) == NULL ||
220 	    (state->output = sshbuf_new()) == NULL ||
221 	    (state->outgoing_packet = sshbuf_new()) == NULL ||
222 	    (state->incoming_packet = sshbuf_new()) == NULL)
223 		goto fail;
224 	TAILQ_INIT(&state->outgoing);
225 	TAILQ_INIT(&ssh->private_keys);
226 	TAILQ_INIT(&ssh->public_keys);
227 	state->connection_in = -1;
228 	state->connection_out = -1;
229 	state->max_packet_size = 32768;
230 	state->packet_timeout_ms = -1;
231 	state->p_send.packets = state->p_read.packets = 0;
232 	state->initialized = 1;
233 	/*
234 	 * ssh_packet_send2() needs to queue packets until
235 	 * we've done the initial key exchange.
236 	 */
237 	state->rekeying = 1;
238 	ssh->state = state;
239 	return ssh;
240  fail:
241 	if (state) {
242 		sshbuf_free(state->input);
243 		sshbuf_free(state->output);
244 		sshbuf_free(state->incoming_packet);
245 		sshbuf_free(state->outgoing_packet);
246 		free(state);
247 	}
248 	free(ssh);
249 	return NULL;
250 }
251 
252 void
253 ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
254 {
255 	ssh->state->hook_in = hook;
256 	ssh->state->hook_in_ctx = ctx;
257 }
258 
259 /* Returns nonzero if rekeying is in progress */
260 int
261 ssh_packet_is_rekeying(struct ssh *ssh)
262 {
263 	return ssh->state->rekeying ||
264 	    (ssh->kex != NULL && ssh->kex->done == 0);
265 }
266 
267 /*
268  * Sets the descriptors used for communication.
269  */
270 struct ssh *
271 ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
272 {
273 	struct session_state *state;
274 	const struct sshcipher *none = cipher_by_name("none");
275 	int r;
276 
277 	if (none == NULL) {
278 		error("%s: cannot load cipher 'none'", __func__);
279 		return NULL;
280 	}
281 	if (ssh == NULL)
282 		ssh = ssh_alloc_session_state();
283 	if (ssh == NULL) {
284 		error("%s: cound not allocate state", __func__);
285 		return NULL;
286 	}
287 	state = ssh->state;
288 	state->connection_in = fd_in;
289 	state->connection_out = fd_out;
290 	if ((r = cipher_init(&state->send_context, none,
291 	    (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
292 	    (r = cipher_init(&state->receive_context, none,
293 	    (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
294 		error("%s: cipher_init failed: %s", __func__, ssh_err(r));
295 		free(ssh); /* XXX need ssh_free_session_state? */
296 		return NULL;
297 	}
298 	state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
299 	/*
300 	 * Cache the IP address of the remote connection for use in error
301 	 * messages that might be generated after the connection has closed.
302 	 */
303 	(void)ssh_remote_ipaddr(ssh);
304 	return ssh;
305 }
306 
307 void
308 ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
309 {
310 	struct session_state *state = ssh->state;
311 
312 	if (timeout <= 0 || count <= 0) {
313 		state->packet_timeout_ms = -1;
314 		return;
315 	}
316 	if ((INT_MAX / 1000) / count < timeout)
317 		state->packet_timeout_ms = INT_MAX;
318 	else
319 		state->packet_timeout_ms = timeout * count * 1000;
320 }
321 
322 void
323 ssh_packet_set_mux(struct ssh *ssh)
324 {
325 	ssh->state->mux = 1;
326 	ssh->state->rekeying = 0;
327 }
328 
329 int
330 ssh_packet_get_mux(struct ssh *ssh)
331 {
332 	return ssh->state->mux;
333 }
334 
335 int
336 ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
337 {
338 	va_list args;
339 	int r;
340 
341 	free(ssh->log_preamble);
342 	if (fmt == NULL)
343 		ssh->log_preamble = NULL;
344 	else {
345 		va_start(args, fmt);
346 		r = vasprintf(&ssh->log_preamble, fmt, args);
347 		va_end(args);
348 		if (r < 0 || ssh->log_preamble == NULL)
349 			return SSH_ERR_ALLOC_FAIL;
350 	}
351 	return 0;
352 }
353 
354 int
355 ssh_packet_stop_discard(struct ssh *ssh)
356 {
357 	struct session_state *state = ssh->state;
358 	int r;
359 
360 	if (state->packet_discard_mac) {
361 		char buf[1024];
362 		size_t dlen = PACKET_MAX_SIZE;
363 
364 		if (dlen > state->packet_discard_mac_already)
365 			dlen -= state->packet_discard_mac_already;
366 		memset(buf, 'a', sizeof(buf));
367 		while (sshbuf_len(state->incoming_packet) < dlen)
368 			if ((r = sshbuf_put(state->incoming_packet, buf,
369 			    sizeof(buf))) != 0)
370 				return r;
371 		(void) mac_compute(state->packet_discard_mac,
372 		    state->p_read.seqnr,
373 		    sshbuf_ptr(state->incoming_packet), dlen,
374 		    NULL, 0);
375 	}
376 	logit("Finished discarding for %.200s port %d",
377 	    ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
378 	return SSH_ERR_MAC_INVALID;
379 }
380 
381 static int
382 ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
383     struct sshmac *mac, size_t mac_already, u_int discard)
384 {
385 	struct session_state *state = ssh->state;
386 	int r;
387 
388 	if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
389 		if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
390 			return r;
391 		return SSH_ERR_MAC_INVALID;
392 	}
393 	/*
394 	 * Record number of bytes over which the mac has already
395 	 * been computed in order to minimize timing attacks.
396 	 */
397 	if (mac && mac->enabled) {
398 		state->packet_discard_mac = mac;
399 		state->packet_discard_mac_already = mac_already;
400 	}
401 	if (sshbuf_len(state->input) >= discard)
402 		return ssh_packet_stop_discard(ssh);
403 	state->packet_discard = discard - sshbuf_len(state->input);
404 	return 0;
405 }
406 
407 /* Returns 1 if remote host is connected via socket, 0 if not. */
408 
409 int
410 ssh_packet_connection_is_on_socket(struct ssh *ssh)
411 {
412 	struct session_state *state;
413 	struct sockaddr_storage from, to;
414 	socklen_t fromlen, tolen;
415 
416 	if (ssh == NULL || ssh->state == NULL)
417 		return 0;
418 
419 	state = ssh->state;
420 	if (state->connection_in == -1 || state->connection_out == -1)
421 		return 0;
422 	/* filedescriptors in and out are the same, so it's a socket */
423 	if (state->connection_in == state->connection_out)
424 		return 1;
425 	fromlen = sizeof(from);
426 	memset(&from, 0, sizeof(from));
427 	if (getpeername(state->connection_in, (struct sockaddr *)&from,
428 	    &fromlen) < 0)
429 		return 0;
430 	tolen = sizeof(to);
431 	memset(&to, 0, sizeof(to));
432 	if (getpeername(state->connection_out, (struct sockaddr *)&to,
433 	    &tolen) < 0)
434 		return 0;
435 	if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
436 		return 0;
437 	if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
438 		return 0;
439 	return 1;
440 }
441 
442 void
443 ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
444 {
445 	if (ibytes)
446 		*ibytes = ssh->state->p_read.bytes;
447 	if (obytes)
448 		*obytes = ssh->state->p_send.bytes;
449 }
450 
451 int
452 ssh_packet_connection_af(struct ssh *ssh)
453 {
454 	struct sockaddr_storage to;
455 	socklen_t tolen = sizeof(to);
456 
457 	memset(&to, 0, sizeof(to));
458 	if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
459 	    &tolen) < 0)
460 		return 0;
461 #ifdef IPV4_IN_IPV6
462 	if (to.ss_family == AF_INET6 &&
463 	    IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
464 		return AF_INET;
465 #endif
466 	return to.ss_family;
467 }
468 
469 /* Sets the connection into non-blocking mode. */
470 
471 void
472 ssh_packet_set_nonblocking(struct ssh *ssh)
473 {
474 	/* Set the socket into non-blocking mode. */
475 	set_nonblock(ssh->state->connection_in);
476 
477 	if (ssh->state->connection_out != ssh->state->connection_in)
478 		set_nonblock(ssh->state->connection_out);
479 }
480 
481 /* Returns the socket used for reading. */
482 
483 int
484 ssh_packet_get_connection_in(struct ssh *ssh)
485 {
486 	return ssh->state->connection_in;
487 }
488 
489 /* Returns the descriptor used for writing. */
490 
491 int
492 ssh_packet_get_connection_out(struct ssh *ssh)
493 {
494 	return ssh->state->connection_out;
495 }
496 
497 /*
498  * Returns the IP-address of the remote host as a string.  The returned
499  * string must not be freed.
500  */
501 
502 const char *
503 ssh_remote_ipaddr(struct ssh *ssh)
504 {
505 	int sock;
506 
507 	/* Check whether we have cached the ipaddr. */
508 	if (ssh->remote_ipaddr == NULL) {
509 		if (ssh_packet_connection_is_on_socket(ssh)) {
510 			sock = ssh->state->connection_in;
511 			ssh->remote_ipaddr = get_peer_ipaddr(sock);
512 			ssh->remote_port = get_peer_port(sock);
513 			ssh->local_ipaddr = get_local_ipaddr(sock);
514 			ssh->local_port = get_local_port(sock);
515 		} else {
516 			ssh->remote_ipaddr = strdup("UNKNOWN");
517 			ssh->remote_port = 65535;
518 			ssh->local_ipaddr = strdup("UNKNOWN");
519 			ssh->local_port = 65535;
520 		}
521 	}
522 	return ssh->remote_ipaddr;
523 }
524 
525 /* Returns the port number of the remote host. */
526 
527 int
528 ssh_remote_port(struct ssh *ssh)
529 {
530 	(void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
531 	return ssh->remote_port;
532 }
533 
534 /*
535  * Returns the IP-address of the local host as a string.  The returned
536  * string must not be freed.
537  */
538 
539 const char *
540 ssh_local_ipaddr(struct ssh *ssh)
541 {
542 	(void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
543 	return ssh->local_ipaddr;
544 }
545 
546 /* Returns the port number of the local host. */
547 
548 int
549 ssh_local_port(struct ssh *ssh)
550 {
551 	(void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
552 	return ssh->local_port;
553 }
554 
555 /* Returns the routing domain of the input socket, or NULL if unavailable */
556 const char *
557 ssh_packet_rdomain_in(struct ssh *ssh)
558 {
559 	if (ssh->rdomain_in != NULL)
560 		return ssh->rdomain_in;
561 	if (!ssh_packet_connection_is_on_socket(ssh))
562 		return NULL;
563 	ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
564 	return ssh->rdomain_in;
565 }
566 
567 /* Closes the connection and clears and frees internal data structures. */
568 
569 static void
570 ssh_packet_close_internal(struct ssh *ssh, int do_close)
571 {
572 	struct session_state *state = ssh->state;
573 	u_int mode;
574 
575 	if (!state->initialized)
576 		return;
577 	state->initialized = 0;
578 	if (do_close) {
579 		if (state->connection_in == state->connection_out) {
580 			close(state->connection_out);
581 		} else {
582 			close(state->connection_in);
583 			close(state->connection_out);
584 		}
585 	}
586 	sshbuf_free(state->input);
587 	sshbuf_free(state->output);
588 	sshbuf_free(state->outgoing_packet);
589 	sshbuf_free(state->incoming_packet);
590 	for (mode = 0; mode < MODE_MAX; mode++) {
591 		kex_free_newkeys(state->newkeys[mode]);	/* current keys */
592 		state->newkeys[mode] = NULL;
593 		ssh_clear_newkeys(ssh, mode);		/* next keys */
594 	}
595 	/* compression state is in shared mem, so we can only release it once */
596 	if (do_close && state->compression_buffer) {
597 		sshbuf_free(state->compression_buffer);
598 		if (state->compression_out_started) {
599 			z_streamp stream = &state->compression_out_stream;
600 			debug("compress outgoing: "
601 			    "raw data %llu, compressed %llu, factor %.2f",
602 				(unsigned long long)stream->total_in,
603 				(unsigned long long)stream->total_out,
604 				stream->total_in == 0 ? 0.0 :
605 				(double) stream->total_out / stream->total_in);
606 			if (state->compression_out_failures == 0)
607 				deflateEnd(stream);
608 		}
609 		if (state->compression_in_started) {
610 			z_streamp stream = &state->compression_in_stream;
611 			debug("compress incoming: "
612 			    "raw data %llu, compressed %llu, factor %.2f",
613 			    (unsigned long long)stream->total_out,
614 			    (unsigned long long)stream->total_in,
615 			    stream->total_out == 0 ? 0.0 :
616 			    (double) stream->total_in / stream->total_out);
617 			if (state->compression_in_failures == 0)
618 				inflateEnd(stream);
619 		}
620 	}
621 	cipher_free(state->send_context);
622 	cipher_free(state->receive_context);
623 	state->send_context = state->receive_context = NULL;
624 	if (do_close) {
625 		free(ssh->remote_ipaddr);
626 		ssh->remote_ipaddr = NULL;
627 		free(ssh->state);
628 		ssh->state = NULL;
629 	}
630 }
631 
632 void
633 ssh_packet_close(struct ssh *ssh)
634 {
635 	ssh_packet_close_internal(ssh, 1);
636 }
637 
638 void
639 ssh_packet_clear_keys(struct ssh *ssh)
640 {
641 	ssh_packet_close_internal(ssh, 0);
642 }
643 
644 /* Sets remote side protocol flags. */
645 
646 void
647 ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
648 {
649 	ssh->state->remote_protocol_flags = protocol_flags;
650 }
651 
652 /* Returns the remote protocol flags set earlier by the above function. */
653 
654 u_int
655 ssh_packet_get_protocol_flags(struct ssh *ssh)
656 {
657 	return ssh->state->remote_protocol_flags;
658 }
659 
660 /*
661  * Starts packet compression from the next packet on in both directions.
662  * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
663  */
664 
665 static int
666 ssh_packet_init_compression(struct ssh *ssh)
667 {
668 	if (!ssh->state->compression_buffer &&
669 	   ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
670 		return SSH_ERR_ALLOC_FAIL;
671 	return 0;
672 }
673 
674 static int
675 start_compression_out(struct ssh *ssh, int level)
676 {
677 	if (level < 1 || level > 9)
678 		return SSH_ERR_INVALID_ARGUMENT;
679 	debug("Enabling compression at level %d.", level);
680 	if (ssh->state->compression_out_started == 1)
681 		deflateEnd(&ssh->state->compression_out_stream);
682 	switch (deflateInit(&ssh->state->compression_out_stream, level)) {
683 	case Z_OK:
684 		ssh->state->compression_out_started = 1;
685 		break;
686 	case Z_MEM_ERROR:
687 		return SSH_ERR_ALLOC_FAIL;
688 	default:
689 		return SSH_ERR_INTERNAL_ERROR;
690 	}
691 	return 0;
692 }
693 
694 static int
695 start_compression_in(struct ssh *ssh)
696 {
697 	if (ssh->state->compression_in_started == 1)
698 		inflateEnd(&ssh->state->compression_in_stream);
699 	switch (inflateInit(&ssh->state->compression_in_stream)) {
700 	case Z_OK:
701 		ssh->state->compression_in_started = 1;
702 		break;
703 	case Z_MEM_ERROR:
704 		return SSH_ERR_ALLOC_FAIL;
705 	default:
706 		return SSH_ERR_INTERNAL_ERROR;
707 	}
708 	return 0;
709 }
710 
711 /* XXX remove need for separate compression buffer */
712 static int
713 compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
714 {
715 	u_char buf[4096];
716 	int r, status;
717 
718 	if (ssh->state->compression_out_started != 1)
719 		return SSH_ERR_INTERNAL_ERROR;
720 
721 	/* This case is not handled below. */
722 	if (sshbuf_len(in) == 0)
723 		return 0;
724 
725 	/* Input is the contents of the input buffer. */
726 	if ((ssh->state->compression_out_stream.next_in =
727 	    sshbuf_mutable_ptr(in)) == NULL)
728 		return SSH_ERR_INTERNAL_ERROR;
729 	ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
730 
731 	/* Loop compressing until deflate() returns with avail_out != 0. */
732 	do {
733 		/* Set up fixed-size output buffer. */
734 		ssh->state->compression_out_stream.next_out = buf;
735 		ssh->state->compression_out_stream.avail_out = sizeof(buf);
736 
737 		/* Compress as much data into the buffer as possible. */
738 		status = deflate(&ssh->state->compression_out_stream,
739 		    Z_PARTIAL_FLUSH);
740 		switch (status) {
741 		case Z_MEM_ERROR:
742 			return SSH_ERR_ALLOC_FAIL;
743 		case Z_OK:
744 			/* Append compressed data to output_buffer. */
745 			if ((r = sshbuf_put(out, buf, sizeof(buf) -
746 			    ssh->state->compression_out_stream.avail_out)) != 0)
747 				return r;
748 			break;
749 		case Z_STREAM_ERROR:
750 		default:
751 			ssh->state->compression_out_failures++;
752 			return SSH_ERR_INVALID_FORMAT;
753 		}
754 	} while (ssh->state->compression_out_stream.avail_out == 0);
755 	return 0;
756 }
757 
758 static int
759 uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
760 {
761 	u_char buf[4096];
762 	int r, status;
763 
764 	if (ssh->state->compression_in_started != 1)
765 		return SSH_ERR_INTERNAL_ERROR;
766 
767 	if ((ssh->state->compression_in_stream.next_in =
768 	    sshbuf_mutable_ptr(in)) == NULL)
769 		return SSH_ERR_INTERNAL_ERROR;
770 	ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
771 
772 	for (;;) {
773 		/* Set up fixed-size output buffer. */
774 		ssh->state->compression_in_stream.next_out = buf;
775 		ssh->state->compression_in_stream.avail_out = sizeof(buf);
776 
777 		status = inflate(&ssh->state->compression_in_stream,
778 		    Z_PARTIAL_FLUSH);
779 		switch (status) {
780 		case Z_OK:
781 			if ((r = sshbuf_put(out, buf, sizeof(buf) -
782 			    ssh->state->compression_in_stream.avail_out)) != 0)
783 				return r;
784 			break;
785 		case Z_BUF_ERROR:
786 			/*
787 			 * Comments in zlib.h say that we should keep calling
788 			 * inflate() until we get an error.  This appears to
789 			 * be the error that we get.
790 			 */
791 			return 0;
792 		case Z_DATA_ERROR:
793 			return SSH_ERR_INVALID_FORMAT;
794 		case Z_MEM_ERROR:
795 			return SSH_ERR_ALLOC_FAIL;
796 		case Z_STREAM_ERROR:
797 		default:
798 			ssh->state->compression_in_failures++;
799 			return SSH_ERR_INTERNAL_ERROR;
800 		}
801 	}
802 	/* NOTREACHED */
803 }
804 
805 void
806 ssh_clear_newkeys(struct ssh *ssh, int mode)
807 {
808 	if (ssh->kex && ssh->kex->newkeys[mode]) {
809 		kex_free_newkeys(ssh->kex->newkeys[mode]);
810 		ssh->kex->newkeys[mode] = NULL;
811 	}
812 }
813 
814 int
815 ssh_set_newkeys(struct ssh *ssh, int mode)
816 {
817 	struct session_state *state = ssh->state;
818 	struct sshenc *enc;
819 	struct sshmac *mac;
820 	struct sshcomp *comp;
821 	struct sshcipher_ctx **ccp;
822 	struct packet_state *ps;
823 	u_int64_t *max_blocks;
824 	const char *wmsg;
825 	int r, crypt_type;
826 
827 	debug2("set_newkeys: mode %d", mode);
828 
829 	if (mode == MODE_OUT) {
830 		ccp = &state->send_context;
831 		crypt_type = CIPHER_ENCRYPT;
832 		ps = &state->p_send;
833 		max_blocks = &state->max_blocks_out;
834 	} else {
835 		ccp = &state->receive_context;
836 		crypt_type = CIPHER_DECRYPT;
837 		ps = &state->p_read;
838 		max_blocks = &state->max_blocks_in;
839 	}
840 	if (state->newkeys[mode] != NULL) {
841 		debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
842 		   "output %llu bytes %llu blocks",
843 		   (unsigned long long)state->p_read.bytes,
844 		   (unsigned long long)state->p_read.blocks,
845 		   (unsigned long long)state->p_send.bytes,
846 		   (unsigned long long)state->p_send.blocks);
847 		cipher_free(*ccp);
848 		*ccp = NULL;
849 		kex_free_newkeys(state->newkeys[mode]);
850 		state->newkeys[mode] = NULL;
851 	}
852 	/* note that both bytes and the seqnr are not reset */
853 	ps->packets = ps->blocks = 0;
854 	/* move newkeys from kex to state */
855 	if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
856 		return SSH_ERR_INTERNAL_ERROR;
857 	ssh->kex->newkeys[mode] = NULL;
858 	enc  = &state->newkeys[mode]->enc;
859 	mac  = &state->newkeys[mode]->mac;
860 	comp = &state->newkeys[mode]->comp;
861 	if (cipher_authlen(enc->cipher) == 0) {
862 		if ((r = mac_init(mac)) != 0)
863 			return r;
864 	}
865 	mac->enabled = 1;
866 	DBG(debug("cipher_init_context: %d", mode));
867 	if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
868 	    enc->iv, enc->iv_len, crypt_type)) != 0)
869 		return r;
870 	if (!state->cipher_warning_done &&
871 	    (wmsg = cipher_warning_message(*ccp)) != NULL) {
872 		error("Warning: %s", wmsg);
873 		state->cipher_warning_done = 1;
874 	}
875 	/* Deleting the keys does not gain extra security */
876 	/* explicit_bzero(enc->iv,  enc->block_size);
877 	   explicit_bzero(enc->key, enc->key_len);
878 	   explicit_bzero(mac->key, mac->key_len); */
879 	if ((comp->type == COMP_ZLIB ||
880 	    (comp->type == COMP_DELAYED &&
881 	     state->after_authentication)) && comp->enabled == 0) {
882 		if ((r = ssh_packet_init_compression(ssh)) < 0)
883 			return r;
884 		if (mode == MODE_OUT) {
885 			if ((r = start_compression_out(ssh, 6)) != 0)
886 				return r;
887 		} else {
888 			if ((r = start_compression_in(ssh)) != 0)
889 				return r;
890 		}
891 		comp->enabled = 1;
892 	}
893 	/*
894 	 * The 2^(blocksize*2) limit is too expensive for 3DES,
895 	 * so enforce a 1GB limit for small blocksizes.
896 	 * See RFC4344 section 3.2.
897 	 */
898 	if (enc->block_size >= 16)
899 		*max_blocks = (u_int64_t)1 << (enc->block_size*2);
900 	else
901 		*max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
902 	if (state->rekey_limit)
903 		*max_blocks = MINIMUM(*max_blocks,
904 		    state->rekey_limit / enc->block_size);
905 	debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
906 	return 0;
907 }
908 
909 #define MAX_PACKETS	(1U<<31)
910 static int
911 ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
912 {
913 	struct session_state *state = ssh->state;
914 	u_int32_t out_blocks;
915 
916 	/* XXX client can't cope with rekeying pre-auth */
917 	if (!state->after_authentication)
918 		return 0;
919 
920 	/* Haven't keyed yet or KEX in progress. */
921 	if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
922 		return 0;
923 
924 	/* Peer can't rekey */
925 	if (ssh->compat & SSH_BUG_NOREKEY)
926 		return 0;
927 
928 	/*
929 	 * Permit one packet in or out per rekey - this allows us to
930 	 * make progress when rekey limits are very small.
931 	 */
932 	if (state->p_send.packets == 0 && state->p_read.packets == 0)
933 		return 0;
934 
935 	/* Time-based rekeying */
936 	if (state->rekey_interval != 0 &&
937 	    (int64_t)state->rekey_time + state->rekey_interval <= monotime())
938 		return 1;
939 
940 	/*
941 	 * Always rekey when MAX_PACKETS sent in either direction
942 	 * As per RFC4344 section 3.1 we do this after 2^31 packets.
943 	 */
944 	if (state->p_send.packets > MAX_PACKETS ||
945 	    state->p_read.packets > MAX_PACKETS)
946 		return 1;
947 
948 	/* Rekey after (cipher-specific) maximum blocks */
949 	out_blocks = ROUNDUP(outbound_packet_len,
950 	    state->newkeys[MODE_OUT]->enc.block_size);
951 	return (state->max_blocks_out &&
952 	    (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
953 	    (state->max_blocks_in &&
954 	    (state->p_read.blocks > state->max_blocks_in));
955 }
956 
957 /*
958  * Delayed compression for SSH2 is enabled after authentication:
959  * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
960  * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
961  */
962 static int
963 ssh_packet_enable_delayed_compress(struct ssh *ssh)
964 {
965 	struct session_state *state = ssh->state;
966 	struct sshcomp *comp = NULL;
967 	int r, mode;
968 
969 	/*
970 	 * Remember that we are past the authentication step, so rekeying
971 	 * with COMP_DELAYED will turn on compression immediately.
972 	 */
973 	state->after_authentication = 1;
974 	for (mode = 0; mode < MODE_MAX; mode++) {
975 		/* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
976 		if (state->newkeys[mode] == NULL)
977 			continue;
978 		comp = &state->newkeys[mode]->comp;
979 		if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
980 			if ((r = ssh_packet_init_compression(ssh)) != 0)
981 				return r;
982 			if (mode == MODE_OUT) {
983 				if ((r = start_compression_out(ssh, 6)) != 0)
984 					return r;
985 			} else {
986 				if ((r = start_compression_in(ssh)) != 0)
987 					return r;
988 			}
989 			comp->enabled = 1;
990 		}
991 	}
992 	return 0;
993 }
994 
995 /* Used to mute debug logging for noisy packet types */
996 int
997 ssh_packet_log_type(u_char type)
998 {
999 	switch (type) {
1000 	case SSH2_MSG_CHANNEL_DATA:
1001 	case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1002 	case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1003 		return 0;
1004 	default:
1005 		return 1;
1006 	}
1007 }
1008 
1009 /*
1010  * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1011  */
1012 int
1013 ssh_packet_send2_wrapped(struct ssh *ssh)
1014 {
1015 	struct session_state *state = ssh->state;
1016 	u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1017 	u_char tmp, padlen, pad = 0;
1018 	u_int authlen = 0, aadlen = 0;
1019 	u_int len;
1020 	struct sshenc *enc   = NULL;
1021 	struct sshmac *mac   = NULL;
1022 	struct sshcomp *comp = NULL;
1023 	int r, block_size;
1024 
1025 	if (state->newkeys[MODE_OUT] != NULL) {
1026 		enc  = &state->newkeys[MODE_OUT]->enc;
1027 		mac  = &state->newkeys[MODE_OUT]->mac;
1028 		comp = &state->newkeys[MODE_OUT]->comp;
1029 		/* disable mac for authenticated encryption */
1030 		if ((authlen = cipher_authlen(enc->cipher)) != 0)
1031 			mac = NULL;
1032 	}
1033 	block_size = enc ? enc->block_size : 8;
1034 	aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1035 
1036 	type = (sshbuf_ptr(state->outgoing_packet))[5];
1037 	if (ssh_packet_log_type(type))
1038 		debug3("send packet: type %u", type);
1039 #ifdef PACKET_DEBUG
1040 	fprintf(stderr, "plain:     ");
1041 	sshbuf_dump(state->outgoing_packet, stderr);
1042 #endif
1043 
1044 	if (comp && comp->enabled) {
1045 		len = sshbuf_len(state->outgoing_packet);
1046 		/* skip header, compress only payload */
1047 		if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1048 			goto out;
1049 		sshbuf_reset(state->compression_buffer);
1050 		if ((r = compress_buffer(ssh, state->outgoing_packet,
1051 		    state->compression_buffer)) != 0)
1052 			goto out;
1053 		sshbuf_reset(state->outgoing_packet);
1054 		if ((r = sshbuf_put(state->outgoing_packet,
1055 		    "\0\0\0\0\0", 5)) != 0 ||
1056 		    (r = sshbuf_putb(state->outgoing_packet,
1057 		    state->compression_buffer)) != 0)
1058 			goto out;
1059 		DBG(debug("compression: raw %d compressed %zd", len,
1060 		    sshbuf_len(state->outgoing_packet)));
1061 	}
1062 
1063 	/* sizeof (packet_len + pad_len + payload) */
1064 	len = sshbuf_len(state->outgoing_packet);
1065 
1066 	/*
1067 	 * calc size of padding, alloc space, get random data,
1068 	 * minimum padding is 4 bytes
1069 	 */
1070 	len -= aadlen; /* packet length is not encrypted for EtM modes */
1071 	padlen = block_size - (len % block_size);
1072 	if (padlen < 4)
1073 		padlen += block_size;
1074 	if (state->extra_pad) {
1075 		tmp = state->extra_pad;
1076 		state->extra_pad =
1077 		    ROUNDUP(state->extra_pad, block_size);
1078 		/* check if roundup overflowed */
1079 		if (state->extra_pad < tmp)
1080 			return SSH_ERR_INVALID_ARGUMENT;
1081 		tmp = (len + padlen) % state->extra_pad;
1082 		/* Check whether pad calculation below will underflow */
1083 		if (tmp > state->extra_pad)
1084 			return SSH_ERR_INVALID_ARGUMENT;
1085 		pad = state->extra_pad - tmp;
1086 		DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1087 		    __func__, pad, len, padlen, state->extra_pad));
1088 		tmp = padlen;
1089 		padlen += pad;
1090 		/* Check whether padlen calculation overflowed */
1091 		if (padlen < tmp)
1092 			return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1093 		state->extra_pad = 0;
1094 	}
1095 	if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1096 		goto out;
1097 	if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1098 		/* random padding */
1099 		arc4random_buf(cp, padlen);
1100 	} else {
1101 		/* clear padding */
1102 		explicit_bzero(cp, padlen);
1103 	}
1104 	/* sizeof (packet_len + pad_len + payload + padding) */
1105 	len = sshbuf_len(state->outgoing_packet);
1106 	cp = sshbuf_mutable_ptr(state->outgoing_packet);
1107 	if (cp == NULL) {
1108 		r = SSH_ERR_INTERNAL_ERROR;
1109 		goto out;
1110 	}
1111 	/* packet_length includes payload, padding and padding length field */
1112 	POKE_U32(cp, len - 4);
1113 	cp[4] = padlen;
1114 	DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1115 	    len, padlen, aadlen));
1116 
1117 	/* compute MAC over seqnr and packet(length fields, payload, padding) */
1118 	if (mac && mac->enabled && !mac->etm) {
1119 		if ((r = mac_compute(mac, state->p_send.seqnr,
1120 		    sshbuf_ptr(state->outgoing_packet), len,
1121 		    macbuf, sizeof(macbuf))) != 0)
1122 			goto out;
1123 		DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1124 	}
1125 	/* encrypt packet and append to output buffer. */
1126 	if ((r = sshbuf_reserve(state->output,
1127 	    sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1128 		goto out;
1129 	if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1130 	    sshbuf_ptr(state->outgoing_packet),
1131 	    len - aadlen, aadlen, authlen)) != 0)
1132 		goto out;
1133 	/* append unencrypted MAC */
1134 	if (mac && mac->enabled) {
1135 		if (mac->etm) {
1136 			/* EtM: compute mac over aadlen + cipher text */
1137 			if ((r = mac_compute(mac, state->p_send.seqnr,
1138 			    cp, len, macbuf, sizeof(macbuf))) != 0)
1139 				goto out;
1140 			DBG(debug("done calc MAC(EtM) out #%d",
1141 			    state->p_send.seqnr));
1142 		}
1143 		if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1144 			goto out;
1145 	}
1146 #ifdef PACKET_DEBUG
1147 	fprintf(stderr, "encrypted: ");
1148 	sshbuf_dump(state->output, stderr);
1149 #endif
1150 	/* increment sequence number for outgoing packets */
1151 	if (++state->p_send.seqnr == 0)
1152 		logit("outgoing seqnr wraps around");
1153 	if (++state->p_send.packets == 0)
1154 		if (!(ssh->compat & SSH_BUG_NOREKEY))
1155 			return SSH_ERR_NEED_REKEY;
1156 	state->p_send.blocks += len / block_size;
1157 	state->p_send.bytes += len;
1158 	sshbuf_reset(state->outgoing_packet);
1159 
1160 	if (type == SSH2_MSG_NEWKEYS)
1161 		r = ssh_set_newkeys(ssh, MODE_OUT);
1162 	else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1163 		r = ssh_packet_enable_delayed_compress(ssh);
1164 	else
1165 		r = 0;
1166  out:
1167 	return r;
1168 }
1169 
1170 /* returns non-zero if the specified packet type is usec by KEX */
1171 static int
1172 ssh_packet_type_is_kex(u_char type)
1173 {
1174 	return
1175 	    type >= SSH2_MSG_TRANSPORT_MIN &&
1176 	    type <= SSH2_MSG_TRANSPORT_MAX &&
1177 	    type != SSH2_MSG_SERVICE_REQUEST &&
1178 	    type != SSH2_MSG_SERVICE_ACCEPT &&
1179 	    type != SSH2_MSG_EXT_INFO;
1180 }
1181 
1182 int
1183 ssh_packet_send2(struct ssh *ssh)
1184 {
1185 	struct session_state *state = ssh->state;
1186 	struct packet *p;
1187 	u_char type;
1188 	int r, need_rekey;
1189 
1190 	if (sshbuf_len(state->outgoing_packet) < 6)
1191 		return SSH_ERR_INTERNAL_ERROR;
1192 	type = sshbuf_ptr(state->outgoing_packet)[5];
1193 	need_rekey = !ssh_packet_type_is_kex(type) &&
1194 	    ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1195 
1196 	/*
1197 	 * During rekeying we can only send key exchange messages.
1198 	 * Queue everything else.
1199 	 */
1200 	if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1201 		if (need_rekey)
1202 			debug3("%s: rekex triggered", __func__);
1203 		debug("enqueue packet: %u", type);
1204 		p = calloc(1, sizeof(*p));
1205 		if (p == NULL)
1206 			return SSH_ERR_ALLOC_FAIL;
1207 		p->type = type;
1208 		p->payload = state->outgoing_packet;
1209 		TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1210 		state->outgoing_packet = sshbuf_new();
1211 		if (state->outgoing_packet == NULL)
1212 			return SSH_ERR_ALLOC_FAIL;
1213 		if (need_rekey) {
1214 			/*
1215 			 * This packet triggered a rekey, so send the
1216 			 * KEXINIT now.
1217 			 * NB. reenters this function via kex_start_rekex().
1218 			 */
1219 			return kex_start_rekex(ssh);
1220 		}
1221 		return 0;
1222 	}
1223 
1224 	/* rekeying starts with sending KEXINIT */
1225 	if (type == SSH2_MSG_KEXINIT)
1226 		state->rekeying = 1;
1227 
1228 	if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1229 		return r;
1230 
1231 	/* after a NEWKEYS message we can send the complete queue */
1232 	if (type == SSH2_MSG_NEWKEYS) {
1233 		state->rekeying = 0;
1234 		state->rekey_time = monotime();
1235 		while ((p = TAILQ_FIRST(&state->outgoing))) {
1236 			type = p->type;
1237 			/*
1238 			 * If this packet triggers a rekex, then skip the
1239 			 * remaining packets in the queue for now.
1240 			 * NB. re-enters this function via kex_start_rekex.
1241 			 */
1242 			if (ssh_packet_need_rekeying(ssh,
1243 			    sshbuf_len(p->payload))) {
1244 				debug3("%s: queued packet triggered rekex",
1245 				    __func__);
1246 				return kex_start_rekex(ssh);
1247 			}
1248 			debug("dequeue packet: %u", type);
1249 			sshbuf_free(state->outgoing_packet);
1250 			state->outgoing_packet = p->payload;
1251 			TAILQ_REMOVE(&state->outgoing, p, next);
1252 			memset(p, 0, sizeof(*p));
1253 			free(p);
1254 			if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1255 				return r;
1256 		}
1257 	}
1258 	return 0;
1259 }
1260 
1261 /*
1262  * Waits until a packet has been received, and returns its type.  Note that
1263  * no other data is processed until this returns, so this function should not
1264  * be used during the interactive session.
1265  */
1266 
1267 int
1268 ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1269 {
1270 	struct session_state *state = ssh->state;
1271 	int len, r, ms_remain;
1272 	fd_set *setp;
1273 	char buf[8192];
1274 	struct timeval timeout, start, *timeoutp = NULL;
1275 
1276 	DBG(debug("packet_read()"));
1277 
1278 	setp = calloc(howmany(state->connection_in + 1,
1279 	    NFDBITS), sizeof(fd_mask));
1280 	if (setp == NULL)
1281 		return SSH_ERR_ALLOC_FAIL;
1282 
1283 	/*
1284 	 * Since we are blocking, ensure that all written packets have
1285 	 * been sent.
1286 	 */
1287 	if ((r = ssh_packet_write_wait(ssh)) != 0)
1288 		goto out;
1289 
1290 	/* Stay in the loop until we have received a complete packet. */
1291 	for (;;) {
1292 		/* Try to read a packet from the buffer. */
1293 		r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1294 		if (r != 0)
1295 			break;
1296 		/* If we got a packet, return it. */
1297 		if (*typep != SSH_MSG_NONE)
1298 			break;
1299 		/*
1300 		 * Otherwise, wait for some data to arrive, add it to the
1301 		 * buffer, and try again.
1302 		 */
1303 		memset(setp, 0, howmany(state->connection_in + 1,
1304 		    NFDBITS) * sizeof(fd_mask));
1305 		FD_SET(state->connection_in, setp);
1306 
1307 		if (state->packet_timeout_ms > 0) {
1308 			ms_remain = state->packet_timeout_ms;
1309 			timeoutp = &timeout;
1310 		}
1311 		/* Wait for some data to arrive. */
1312 		for (;;) {
1313 			if (state->packet_timeout_ms != -1) {
1314 				ms_to_timeval(&timeout, ms_remain);
1315 				monotime_tv(&start);
1316 			}
1317 			if ((r = select(state->connection_in + 1, setp,
1318 			    NULL, NULL, timeoutp)) >= 0)
1319 				break;
1320 			if (errno != EAGAIN && errno != EINTR &&
1321 			    errno != EWOULDBLOCK) {
1322 				r = SSH_ERR_SYSTEM_ERROR;
1323 				goto out;
1324 			}
1325 			if (state->packet_timeout_ms == -1)
1326 				continue;
1327 			ms_subtract_diff(&start, &ms_remain);
1328 			if (ms_remain <= 0) {
1329 				r = 0;
1330 				break;
1331 			}
1332 		}
1333 		if (r == 0) {
1334 			r = SSH_ERR_CONN_TIMEOUT;
1335 			goto out;
1336 		}
1337 		/* Read data from the socket. */
1338 		len = read(state->connection_in, buf, sizeof(buf));
1339 		if (len == 0) {
1340 			r = SSH_ERR_CONN_CLOSED;
1341 			goto out;
1342 		}
1343 		if (len < 0) {
1344 			r = SSH_ERR_SYSTEM_ERROR;
1345 			goto out;
1346 		}
1347 
1348 		/* Append it to the buffer. */
1349 		if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1350 			goto out;
1351 	}
1352  out:
1353 	free(setp);
1354 	return r;
1355 }
1356 
1357 int
1358 ssh_packet_read(struct ssh *ssh)
1359 {
1360 	u_char type;
1361 	int r;
1362 
1363 	if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1364 		fatal("%s: %s", __func__, ssh_err(r));
1365 	return type;
1366 }
1367 
1368 /*
1369  * Waits until a packet has been received, verifies that its type matches
1370  * that given, and gives a fatal error and exits if there is a mismatch.
1371  */
1372 
1373 int
1374 ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1375 {
1376 	int r;
1377 	u_char type;
1378 
1379 	if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1380 		return r;
1381 	if (type != expected_type) {
1382 		if ((r = sshpkt_disconnect(ssh,
1383 		    "Protocol error: expected packet type %d, got %d",
1384 		    expected_type, type)) != 0)
1385 			return r;
1386 		return SSH_ERR_PROTOCOL_ERROR;
1387 	}
1388 	return 0;
1389 }
1390 
1391 static int
1392 ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1393 {
1394 	struct session_state *state = ssh->state;
1395 	const u_char *cp;
1396 	size_t need;
1397 	int r;
1398 
1399 	if (ssh->kex)
1400 		return SSH_ERR_INTERNAL_ERROR;
1401 	*typep = SSH_MSG_NONE;
1402 	cp = sshbuf_ptr(state->input);
1403 	if (state->packlen == 0) {
1404 		if (sshbuf_len(state->input) < 4 + 1)
1405 			return 0; /* packet is incomplete */
1406 		state->packlen = PEEK_U32(cp);
1407 		if (state->packlen < 4 + 1 ||
1408 		    state->packlen > PACKET_MAX_SIZE)
1409 			return SSH_ERR_MESSAGE_INCOMPLETE;
1410 	}
1411 	need = state->packlen + 4;
1412 	if (sshbuf_len(state->input) < need)
1413 		return 0; /* packet is incomplete */
1414 	sshbuf_reset(state->incoming_packet);
1415 	if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1416 	    state->packlen)) != 0 ||
1417 	    (r = sshbuf_consume(state->input, need)) != 0 ||
1418 	    (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1419 	    (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1420 		return r;
1421 	if (ssh_packet_log_type(*typep))
1422 		debug3("%s: type %u", __func__, *typep);
1423 	/* sshbuf_dump(state->incoming_packet, stderr); */
1424 	/* reset for next packet */
1425 	state->packlen = 0;
1426 	return r;
1427 }
1428 
1429 int
1430 ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1431 {
1432 	struct session_state *state = ssh->state;
1433 	u_int padlen, need;
1434 	u_char *cp;
1435 	u_int maclen, aadlen = 0, authlen = 0, block_size;
1436 	struct sshenc *enc   = NULL;
1437 	struct sshmac *mac   = NULL;
1438 	struct sshcomp *comp = NULL;
1439 	int r;
1440 
1441 	if (state->mux)
1442 		return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1443 
1444 	*typep = SSH_MSG_NONE;
1445 
1446 	if (state->packet_discard)
1447 		return 0;
1448 
1449 	if (state->newkeys[MODE_IN] != NULL) {
1450 		enc  = &state->newkeys[MODE_IN]->enc;
1451 		mac  = &state->newkeys[MODE_IN]->mac;
1452 		comp = &state->newkeys[MODE_IN]->comp;
1453 		/* disable mac for authenticated encryption */
1454 		if ((authlen = cipher_authlen(enc->cipher)) != 0)
1455 			mac = NULL;
1456 	}
1457 	maclen = mac && mac->enabled ? mac->mac_len : 0;
1458 	block_size = enc ? enc->block_size : 8;
1459 	aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1460 
1461 	if (aadlen && state->packlen == 0) {
1462 		if (cipher_get_length(state->receive_context,
1463 		    &state->packlen, state->p_read.seqnr,
1464 		    sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1465 			return 0;
1466 		if (state->packlen < 1 + 4 ||
1467 		    state->packlen > PACKET_MAX_SIZE) {
1468 #ifdef PACKET_DEBUG
1469 			sshbuf_dump(state->input, stderr);
1470 #endif
1471 			logit("Bad packet length %u.", state->packlen);
1472 			if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1473 				return r;
1474 			return SSH_ERR_CONN_CORRUPT;
1475 		}
1476 		sshbuf_reset(state->incoming_packet);
1477 	} else if (state->packlen == 0) {
1478 		/*
1479 		 * check if input size is less than the cipher block size,
1480 		 * decrypt first block and extract length of incoming packet
1481 		 */
1482 		if (sshbuf_len(state->input) < block_size)
1483 			return 0;
1484 		sshbuf_reset(state->incoming_packet);
1485 		if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1486 		    &cp)) != 0)
1487 			goto out;
1488 		if ((r = cipher_crypt(state->receive_context,
1489 		    state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1490 		    block_size, 0, 0)) != 0)
1491 			goto out;
1492 		state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1493 		if (state->packlen < 1 + 4 ||
1494 		    state->packlen > PACKET_MAX_SIZE) {
1495 #ifdef PACKET_DEBUG
1496 			fprintf(stderr, "input: \n");
1497 			sshbuf_dump(state->input, stderr);
1498 			fprintf(stderr, "incoming_packet: \n");
1499 			sshbuf_dump(state->incoming_packet, stderr);
1500 #endif
1501 			logit("Bad packet length %u.", state->packlen);
1502 			return ssh_packet_start_discard(ssh, enc, mac, 0,
1503 			    PACKET_MAX_SIZE);
1504 		}
1505 		if ((r = sshbuf_consume(state->input, block_size)) != 0)
1506 			goto out;
1507 	}
1508 	DBG(debug("input: packet len %u", state->packlen+4));
1509 
1510 	if (aadlen) {
1511 		/* only the payload is encrypted */
1512 		need = state->packlen;
1513 	} else {
1514 		/*
1515 		 * the payload size and the payload are encrypted, but we
1516 		 * have a partial packet of block_size bytes
1517 		 */
1518 		need = 4 + state->packlen - block_size;
1519 	}
1520 	DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1521 	    " aadlen %d", block_size, need, maclen, authlen, aadlen));
1522 	if (need % block_size != 0) {
1523 		logit("padding error: need %d block %d mod %d",
1524 		    need, block_size, need % block_size);
1525 		return ssh_packet_start_discard(ssh, enc, mac, 0,
1526 		    PACKET_MAX_SIZE - block_size);
1527 	}
1528 	/*
1529 	 * check if the entire packet has been received and
1530 	 * decrypt into incoming_packet:
1531 	 * 'aadlen' bytes are unencrypted, but authenticated.
1532 	 * 'need' bytes are encrypted, followed by either
1533 	 * 'authlen' bytes of authentication tag or
1534 	 * 'maclen' bytes of message authentication code.
1535 	 */
1536 	if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1537 		return 0; /* packet is incomplete */
1538 #ifdef PACKET_DEBUG
1539 	fprintf(stderr, "read_poll enc/full: ");
1540 	sshbuf_dump(state->input, stderr);
1541 #endif
1542 	/* EtM: check mac over encrypted input */
1543 	if (mac && mac->enabled && mac->etm) {
1544 		if ((r = mac_check(mac, state->p_read.seqnr,
1545 		    sshbuf_ptr(state->input), aadlen + need,
1546 		    sshbuf_ptr(state->input) + aadlen + need + authlen,
1547 		    maclen)) != 0) {
1548 			if (r == SSH_ERR_MAC_INVALID)
1549 				logit("Corrupted MAC on input.");
1550 			goto out;
1551 		}
1552 	}
1553 	if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1554 	    &cp)) != 0)
1555 		goto out;
1556 	if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1557 	    sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1558 		goto out;
1559 	if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1560 		goto out;
1561 	if (mac && mac->enabled) {
1562 		/* Not EtM: check MAC over cleartext */
1563 		if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1564 		    sshbuf_ptr(state->incoming_packet),
1565 		    sshbuf_len(state->incoming_packet),
1566 		    sshbuf_ptr(state->input), maclen)) != 0) {
1567 			if (r != SSH_ERR_MAC_INVALID)
1568 				goto out;
1569 			logit("Corrupted MAC on input.");
1570 			if (need + block_size > PACKET_MAX_SIZE)
1571 				return SSH_ERR_INTERNAL_ERROR;
1572 			return ssh_packet_start_discard(ssh, enc, mac,
1573 			    sshbuf_len(state->incoming_packet),
1574 			    PACKET_MAX_SIZE - need - block_size);
1575 		}
1576 		/* Remove MAC from input buffer */
1577 		DBG(debug("MAC #%d ok", state->p_read.seqnr));
1578 		if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1579 			goto out;
1580 	}
1581 	if (seqnr_p != NULL)
1582 		*seqnr_p = state->p_read.seqnr;
1583 	if (++state->p_read.seqnr == 0)
1584 		logit("incoming seqnr wraps around");
1585 	if (++state->p_read.packets == 0)
1586 		if (!(ssh->compat & SSH_BUG_NOREKEY))
1587 			return SSH_ERR_NEED_REKEY;
1588 	state->p_read.blocks += (state->packlen + 4) / block_size;
1589 	state->p_read.bytes += state->packlen + 4;
1590 
1591 	/* get padlen */
1592 	padlen = sshbuf_ptr(state->incoming_packet)[4];
1593 	DBG(debug("input: padlen %d", padlen));
1594 	if (padlen < 4)	{
1595 		if ((r = sshpkt_disconnect(ssh,
1596 		    "Corrupted padlen %d on input.", padlen)) != 0 ||
1597 		    (r = ssh_packet_write_wait(ssh)) != 0)
1598 			return r;
1599 		return SSH_ERR_CONN_CORRUPT;
1600 	}
1601 
1602 	/* skip packet size + padlen, discard padding */
1603 	if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1604 	    ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1605 		goto out;
1606 
1607 	DBG(debug("input: len before de-compress %zd",
1608 	    sshbuf_len(state->incoming_packet)));
1609 	if (comp && comp->enabled) {
1610 		sshbuf_reset(state->compression_buffer);
1611 		if ((r = uncompress_buffer(ssh, state->incoming_packet,
1612 		    state->compression_buffer)) != 0)
1613 			goto out;
1614 		sshbuf_reset(state->incoming_packet);
1615 		if ((r = sshbuf_putb(state->incoming_packet,
1616 		    state->compression_buffer)) != 0)
1617 			goto out;
1618 		DBG(debug("input: len after de-compress %zd",
1619 		    sshbuf_len(state->incoming_packet)));
1620 	}
1621 	/*
1622 	 * get packet type, implies consume.
1623 	 * return length of payload (without type field)
1624 	 */
1625 	if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1626 		goto out;
1627 	if (ssh_packet_log_type(*typep))
1628 		debug3("receive packet: type %u", *typep);
1629 	if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1630 		if ((r = sshpkt_disconnect(ssh,
1631 		    "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1632 		    (r = ssh_packet_write_wait(ssh)) != 0)
1633 			return r;
1634 		return SSH_ERR_PROTOCOL_ERROR;
1635 	}
1636 	if (state->hook_in != NULL &&
1637 	    (r = state->hook_in(ssh, state->incoming_packet, typep,
1638 	    state->hook_in_ctx)) != 0)
1639 		return r;
1640 	if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1641 		r = ssh_packet_enable_delayed_compress(ssh);
1642 	else
1643 		r = 0;
1644 #ifdef PACKET_DEBUG
1645 	fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1646 	sshbuf_dump(state->incoming_packet, stderr);
1647 #endif
1648 	/* reset for next packet */
1649 	state->packlen = 0;
1650 
1651 	/* do we need to rekey? */
1652 	if (ssh_packet_need_rekeying(ssh, 0)) {
1653 		debug3("%s: rekex triggered", __func__);
1654 		if ((r = kex_start_rekex(ssh)) != 0)
1655 			return r;
1656 	}
1657  out:
1658 	return r;
1659 }
1660 
1661 int
1662 ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1663 {
1664 	struct session_state *state = ssh->state;
1665 	u_int reason, seqnr;
1666 	int r;
1667 	u_char *msg;
1668 
1669 	for (;;) {
1670 		msg = NULL;
1671 		r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1672 		if (r != 0)
1673 			return r;
1674 		if (*typep) {
1675 			state->keep_alive_timeouts = 0;
1676 			DBG(debug("received packet type %d", *typep));
1677 		}
1678 		switch (*typep) {
1679 		case SSH2_MSG_IGNORE:
1680 			debug3("Received SSH2_MSG_IGNORE");
1681 			break;
1682 		case SSH2_MSG_DEBUG:
1683 			if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1684 			    (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1685 			    (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1686 				free(msg);
1687 				return r;
1688 			}
1689 			debug("Remote: %.900s", msg);
1690 			free(msg);
1691 			break;
1692 		case SSH2_MSG_DISCONNECT:
1693 			if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1694 			    (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1695 				return r;
1696 			/* Ignore normal client exit notifications */
1697 			do_log2(ssh->state->server_side &&
1698 			    reason == SSH2_DISCONNECT_BY_APPLICATION ?
1699 			    SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1700 			    "Received disconnect from %s port %d:"
1701 			    "%u: %.400s", ssh_remote_ipaddr(ssh),
1702 			    ssh_remote_port(ssh), reason, msg);
1703 			free(msg);
1704 			return SSH_ERR_DISCONNECTED;
1705 		case SSH2_MSG_UNIMPLEMENTED:
1706 			if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1707 				return r;
1708 			debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1709 			    seqnr);
1710 			break;
1711 		default:
1712 			return 0;
1713 		}
1714 	}
1715 }
1716 
1717 /*
1718  * Buffers the given amount of input characters.  This is intended to be used
1719  * together with packet_read_poll.
1720  */
1721 
1722 int
1723 ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1724 {
1725 	struct session_state *state = ssh->state;
1726 	int r;
1727 
1728 	if (state->packet_discard) {
1729 		state->keep_alive_timeouts = 0; /* ?? */
1730 		if (len >= state->packet_discard) {
1731 			if ((r = ssh_packet_stop_discard(ssh)) != 0)
1732 				return r;
1733 		}
1734 		state->packet_discard -= len;
1735 		return 0;
1736 	}
1737 	if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1738 		return r;
1739 
1740 	return 0;
1741 }
1742 
1743 int
1744 ssh_packet_remaining(struct ssh *ssh)
1745 {
1746 	return sshbuf_len(ssh->state->incoming_packet);
1747 }
1748 
1749 /*
1750  * Sends a diagnostic message from the server to the client.  This message
1751  * can be sent at any time (but not while constructing another message). The
1752  * message is printed immediately, but only if the client is being executed
1753  * in verbose mode.  These messages are primarily intended to ease debugging
1754  * authentication problems.   The length of the formatted message must not
1755  * exceed 1024 bytes.  This will automatically call ssh_packet_write_wait.
1756  */
1757 void
1758 ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1759 {
1760 	char buf[1024];
1761 	va_list args;
1762 	int r;
1763 
1764 	if ((ssh->compat & SSH_BUG_DEBUG))
1765 		return;
1766 
1767 	va_start(args, fmt);
1768 	vsnprintf(buf, sizeof(buf), fmt, args);
1769 	va_end(args);
1770 
1771 	debug3("sending debug message: %s", buf);
1772 
1773 	if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1774 	    (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1775 	    (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1776 	    (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1777 	    (r = sshpkt_send(ssh)) != 0 ||
1778 	    (r = ssh_packet_write_wait(ssh)) != 0)
1779 		fatal("%s: %s", __func__, ssh_err(r));
1780 }
1781 
1782 void
1783 sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1784 {
1785 	snprintf(s, l, "%.200s%s%s port %d",
1786 	    ssh->log_preamble ? ssh->log_preamble : "",
1787 	    ssh->log_preamble ? " " : "",
1788 	    ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1789 }
1790 
1791 /*
1792  * Pretty-print connection-terminating errors and exit.
1793  */
1794 void
1795 sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1796 {
1797 	char remote_id[512];
1798 
1799 	sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1800 
1801 	switch (r) {
1802 	case SSH_ERR_CONN_CLOSED:
1803 		ssh_packet_clear_keys(ssh);
1804 		logdie("Connection closed by %s", remote_id);
1805 	case SSH_ERR_CONN_TIMEOUT:
1806 		ssh_packet_clear_keys(ssh);
1807 		logdie("Connection %s %s timed out",
1808 		    ssh->state->server_side ? "from" : "to", remote_id);
1809 	case SSH_ERR_DISCONNECTED:
1810 		ssh_packet_clear_keys(ssh);
1811 		logdie("Disconnected from %s", remote_id);
1812 	case SSH_ERR_SYSTEM_ERROR:
1813 		if (errno == ECONNRESET) {
1814 			ssh_packet_clear_keys(ssh);
1815 			logdie("Connection reset by %s", remote_id);
1816 		}
1817 		/* FALLTHROUGH */
1818 	case SSH_ERR_NO_CIPHER_ALG_MATCH:
1819 	case SSH_ERR_NO_MAC_ALG_MATCH:
1820 	case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1821 	case SSH_ERR_NO_KEX_ALG_MATCH:
1822 	case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1823 		if (ssh && ssh->kex && ssh->kex->failed_choice) {
1824 			ssh_packet_clear_keys(ssh);
1825 			logdie("Unable to negotiate with %s: %s. "
1826 			    "Their offer: %s", remote_id, ssh_err(r),
1827 			    ssh->kex->failed_choice);
1828 		}
1829 		/* FALLTHROUGH */
1830 	default:
1831 		ssh_packet_clear_keys(ssh);
1832 		logdie("%s%sConnection %s %s: %s",
1833 		    tag != NULL ? tag : "", tag != NULL ? ": " : "",
1834 		    ssh->state->server_side ? "from" : "to",
1835 		    remote_id, ssh_err(r));
1836 	}
1837 }
1838 
1839 /*
1840  * Logs the error plus constructs and sends a disconnect packet, closes the
1841  * connection, and exits.  This function never returns. The error message
1842  * should not contain a newline.  The length of the formatted message must
1843  * not exceed 1024 bytes.
1844  */
1845 void
1846 ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1847 {
1848 	char buf[1024], remote_id[512];
1849 	va_list args;
1850 	static int disconnecting = 0;
1851 	int r;
1852 
1853 	if (disconnecting)	/* Guard against recursive invocations. */
1854 		fatal("packet_disconnect called recursively.");
1855 	disconnecting = 1;
1856 
1857 	/*
1858 	 * Format the message.  Note that the caller must make sure the
1859 	 * message is of limited size.
1860 	 */
1861 	sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1862 	va_start(args, fmt);
1863 	vsnprintf(buf, sizeof(buf), fmt, args);
1864 	va_end(args);
1865 
1866 	/* Display the error locally */
1867 	logit("Disconnecting %s: %.100s", remote_id, buf);
1868 
1869 	/*
1870 	 * Send the disconnect message to the other side, and wait
1871 	 * for it to get sent.
1872 	 */
1873 	if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1874 		sshpkt_fatal(ssh, __func__, r);
1875 
1876 	if ((r = ssh_packet_write_wait(ssh)) != 0)
1877 		sshpkt_fatal(ssh, __func__, r);
1878 
1879 	/* Close the connection. */
1880 	ssh_packet_close(ssh);
1881 	cleanup_exit(255);
1882 }
1883 
1884 /*
1885  * Checks if there is any buffered output, and tries to write some of
1886  * the output.
1887  */
1888 int
1889 ssh_packet_write_poll(struct ssh *ssh)
1890 {
1891 	struct session_state *state = ssh->state;
1892 	int len = sshbuf_len(state->output);
1893 	int r;
1894 
1895 	if (len > 0) {
1896 		len = write(state->connection_out,
1897 		    sshbuf_ptr(state->output), len);
1898 		if (len == -1) {
1899 			if (errno == EINTR || errno == EAGAIN ||
1900 			    errno == EWOULDBLOCK)
1901 				return 0;
1902 			return SSH_ERR_SYSTEM_ERROR;
1903 		}
1904 		if (len == 0)
1905 			return SSH_ERR_CONN_CLOSED;
1906 		if ((r = sshbuf_consume(state->output, len)) != 0)
1907 			return r;
1908 	}
1909 	return 0;
1910 }
1911 
1912 /*
1913  * Calls packet_write_poll repeatedly until all pending output data has been
1914  * written.
1915  */
1916 int
1917 ssh_packet_write_wait(struct ssh *ssh)
1918 {
1919 	fd_set *setp;
1920 	int ret, r, ms_remain = 0;
1921 	struct timeval start, timeout, *timeoutp = NULL;
1922 	struct session_state *state = ssh->state;
1923 
1924 	setp = calloc(howmany(state->connection_out + 1,
1925 	    NFDBITS), sizeof(fd_mask));
1926 	if (setp == NULL)
1927 		return SSH_ERR_ALLOC_FAIL;
1928 	if ((r = ssh_packet_write_poll(ssh)) != 0) {
1929 		free(setp);
1930 		return r;
1931 	}
1932 	while (ssh_packet_have_data_to_write(ssh)) {
1933 		memset(setp, 0, howmany(state->connection_out + 1,
1934 		    NFDBITS) * sizeof(fd_mask));
1935 		FD_SET(state->connection_out, setp);
1936 
1937 		if (state->packet_timeout_ms > 0) {
1938 			ms_remain = state->packet_timeout_ms;
1939 			timeoutp = &timeout;
1940 		}
1941 		for (;;) {
1942 			if (state->packet_timeout_ms != -1) {
1943 				ms_to_timeval(&timeout, ms_remain);
1944 				monotime_tv(&start);
1945 			}
1946 			if ((ret = select(state->connection_out + 1,
1947 			    NULL, setp, NULL, timeoutp)) >= 0)
1948 				break;
1949 			if (errno != EAGAIN && errno != EINTR &&
1950 			    errno != EWOULDBLOCK)
1951 				break;
1952 			if (state->packet_timeout_ms == -1)
1953 				continue;
1954 			ms_subtract_diff(&start, &ms_remain);
1955 			if (ms_remain <= 0) {
1956 				ret = 0;
1957 				break;
1958 			}
1959 		}
1960 		if (ret == 0) {
1961 			free(setp);
1962 			return SSH_ERR_CONN_TIMEOUT;
1963 		}
1964 		if ((r = ssh_packet_write_poll(ssh)) != 0) {
1965 			free(setp);
1966 			return r;
1967 		}
1968 	}
1969 	free(setp);
1970 	return 0;
1971 }
1972 
1973 /* Returns true if there is buffered data to write to the connection. */
1974 
1975 int
1976 ssh_packet_have_data_to_write(struct ssh *ssh)
1977 {
1978 	return sshbuf_len(ssh->state->output) != 0;
1979 }
1980 
1981 /* Returns true if there is not too much data to write to the connection. */
1982 
1983 int
1984 ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1985 {
1986 	if (ssh->state->interactive_mode)
1987 		return sshbuf_len(ssh->state->output) < 16384;
1988 	else
1989 		return sshbuf_len(ssh->state->output) < 128 * 1024;
1990 }
1991 
1992 void
1993 ssh_packet_set_tos(struct ssh *ssh, int tos)
1994 {
1995 #ifndef IP_TOS_IS_BROKEN
1996 	if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
1997 		return;
1998 	switch (ssh_packet_connection_af(ssh)) {
1999 # ifdef IP_TOS
2000 	case AF_INET:
2001 		debug3("%s: set IP_TOS 0x%02x", __func__, tos);
2002 		if (setsockopt(ssh->state->connection_in,
2003 		    IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2004 			error("setsockopt IP_TOS %d: %.100s:",
2005 			    tos, strerror(errno));
2006 		break;
2007 # endif /* IP_TOS */
2008 # ifdef IPV6_TCLASS
2009 	case AF_INET6:
2010 		debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
2011 		if (setsockopt(ssh->state->connection_in,
2012 		    IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2013 			error("setsockopt IPV6_TCLASS %d: %.100s:",
2014 			    tos, strerror(errno));
2015 		break;
2016 # endif /* IPV6_TCLASS */
2017 	}
2018 #endif /* IP_TOS_IS_BROKEN */
2019 }
2020 
2021 /* Informs that the current session is interactive.  Sets IP flags for that. */
2022 
2023 void
2024 ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
2025 {
2026 	struct session_state *state = ssh->state;
2027 
2028 	if (state->set_interactive_called)
2029 		return;
2030 	state->set_interactive_called = 1;
2031 
2032 	/* Record that we are in interactive mode. */
2033 	state->interactive_mode = interactive;
2034 
2035 	/* Only set socket options if using a socket.  */
2036 	if (!ssh_packet_connection_is_on_socket(ssh))
2037 		return;
2038 	set_nodelay(state->connection_in);
2039 	ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2040 	    qos_bulk);
2041 }
2042 
2043 /* Returns true if the current connection is interactive. */
2044 
2045 int
2046 ssh_packet_is_interactive(struct ssh *ssh)
2047 {
2048 	return ssh->state->interactive_mode;
2049 }
2050 
2051 int
2052 ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
2053 {
2054 	struct session_state *state = ssh->state;
2055 
2056 	if (state->set_maxsize_called) {
2057 		logit("packet_set_maxsize: called twice: old %d new %d",
2058 		    state->max_packet_size, s);
2059 		return -1;
2060 	}
2061 	if (s < 4 * 1024 || s > 1024 * 1024) {
2062 		logit("packet_set_maxsize: bad size %d", s);
2063 		return -1;
2064 	}
2065 	state->set_maxsize_called = 1;
2066 	debug("packet_set_maxsize: setting to %d", s);
2067 	state->max_packet_size = s;
2068 	return s;
2069 }
2070 
2071 int
2072 ssh_packet_inc_alive_timeouts(struct ssh *ssh)
2073 {
2074 	return ++ssh->state->keep_alive_timeouts;
2075 }
2076 
2077 void
2078 ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
2079 {
2080 	ssh->state->keep_alive_timeouts = ka;
2081 }
2082 
2083 u_int
2084 ssh_packet_get_maxsize(struct ssh *ssh)
2085 {
2086 	return ssh->state->max_packet_size;
2087 }
2088 
2089 void
2090 ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
2091 {
2092 	debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2093 	    (unsigned int)seconds);
2094 	ssh->state->rekey_limit = bytes;
2095 	ssh->state->rekey_interval = seconds;
2096 }
2097 
2098 time_t
2099 ssh_packet_get_rekey_timeout(struct ssh *ssh)
2100 {
2101 	time_t seconds;
2102 
2103 	seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
2104 	    monotime();
2105 	return (seconds <= 0 ? 1 : seconds);
2106 }
2107 
2108 void
2109 ssh_packet_set_server(struct ssh *ssh)
2110 {
2111 	ssh->state->server_side = 1;
2112 }
2113 
2114 void
2115 ssh_packet_set_authenticated(struct ssh *ssh)
2116 {
2117 	ssh->state->after_authentication = 1;
2118 }
2119 
2120 void *
2121 ssh_packet_get_input(struct ssh *ssh)
2122 {
2123 	return (void *)ssh->state->input;
2124 }
2125 
2126 void *
2127 ssh_packet_get_output(struct ssh *ssh)
2128 {
2129 	return (void *)ssh->state->output;
2130 }
2131 
2132 /* Reset after_authentication and reset compression in post-auth privsep */
2133 static int
2134 ssh_packet_set_postauth(struct ssh *ssh)
2135 {
2136 	int r;
2137 
2138 	debug("%s: called", __func__);
2139 	/* This was set in net child, but is not visible in user child */
2140 	ssh->state->after_authentication = 1;
2141 	ssh->state->rekeying = 0;
2142 	if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2143 		return r;
2144 	return 0;
2145 }
2146 
2147 /* Packet state (de-)serialization for privsep */
2148 
2149 /* turn kex into a blob for packet state serialization */
2150 static int
2151 kex_to_blob(struct sshbuf *m, struct kex *kex)
2152 {
2153 	int r;
2154 
2155 	if ((r = sshbuf_put_string(m, kex->session_id,
2156 	    kex->session_id_len)) != 0 ||
2157 	    (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2158 	    (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
2159 	    (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2160 	    (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
2161 	    (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2162 	    (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2163 	    (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2164 	    (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2165 	    (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2166 	    (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2167 		return r;
2168 	return 0;
2169 }
2170 
2171 /* turn key exchange results into a blob for packet state serialization */
2172 static int
2173 newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2174 {
2175 	struct sshbuf *b;
2176 	struct sshcipher_ctx *cc;
2177 	struct sshcomp *comp;
2178 	struct sshenc *enc;
2179 	struct sshmac *mac;
2180 	struct newkeys *newkey;
2181 	int r;
2182 
2183 	if ((newkey = ssh->state->newkeys[mode]) == NULL)
2184 		return SSH_ERR_INTERNAL_ERROR;
2185 	enc = &newkey->enc;
2186 	mac = &newkey->mac;
2187 	comp = &newkey->comp;
2188 	cc = (mode == MODE_OUT) ? ssh->state->send_context :
2189 	    ssh->state->receive_context;
2190 	if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2191 		return r;
2192 	if ((b = sshbuf_new()) == NULL)
2193 		return SSH_ERR_ALLOC_FAIL;
2194 	if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2195 	    (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2196 	    (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2197 	    (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2198 	    (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2199 		goto out;
2200 	if (cipher_authlen(enc->cipher) == 0) {
2201 		if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2202 		    (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2203 		    (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2204 			goto out;
2205 	}
2206 	if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2207 	    (r = sshbuf_put_cstring(b, comp->name)) != 0)
2208 		goto out;
2209 	r = sshbuf_put_stringb(m, b);
2210  out:
2211 	sshbuf_free(b);
2212 	return r;
2213 }
2214 
2215 /* serialize packet state into a blob */
2216 int
2217 ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2218 {
2219 	struct session_state *state = ssh->state;
2220 	int r;
2221 
2222 	if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2223 	    (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2224 	    (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2225 	    (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2226 	    (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2227 	    (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2228 	    (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2229 	    (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2230 	    (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2231 	    (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2232 	    (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2233 	    (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2234 	    (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2235 	    (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2236 	    (r = sshbuf_put_stringb(m, state->output)) != 0)
2237 		return r;
2238 
2239 	return 0;
2240 }
2241 
2242 /* restore key exchange results from blob for packet state de-serialization */
2243 static int
2244 newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2245 {
2246 	struct sshbuf *b = NULL;
2247 	struct sshcomp *comp;
2248 	struct sshenc *enc;
2249 	struct sshmac *mac;
2250 	struct newkeys *newkey = NULL;
2251 	size_t keylen, ivlen, maclen;
2252 	int r;
2253 
2254 	if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2255 		r = SSH_ERR_ALLOC_FAIL;
2256 		goto out;
2257 	}
2258 	if ((r = sshbuf_froms(m, &b)) != 0)
2259 		goto out;
2260 #ifdef DEBUG_PK
2261 	sshbuf_dump(b, stderr);
2262 #endif
2263 	enc = &newkey->enc;
2264 	mac = &newkey->mac;
2265 	comp = &newkey->comp;
2266 
2267 	if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2268 	    (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2269 	    (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2270 	    (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2271 	    (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2272 		goto out;
2273 	if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2274 		r = SSH_ERR_INVALID_FORMAT;
2275 		goto out;
2276 	}
2277 	if (cipher_authlen(enc->cipher) == 0) {
2278 		if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2279 			goto out;
2280 		if ((r = mac_setup(mac, mac->name)) != 0)
2281 			goto out;
2282 		if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2283 		    (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2284 			goto out;
2285 		if (maclen > mac->key_len) {
2286 			r = SSH_ERR_INVALID_FORMAT;
2287 			goto out;
2288 		}
2289 		mac->key_len = maclen;
2290 	}
2291 	if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2292 	    (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2293 		goto out;
2294 	if (sshbuf_len(b) != 0) {
2295 		r = SSH_ERR_INVALID_FORMAT;
2296 		goto out;
2297 	}
2298 	enc->key_len = keylen;
2299 	enc->iv_len = ivlen;
2300 	ssh->kex->newkeys[mode] = newkey;
2301 	newkey = NULL;
2302 	r = 0;
2303  out:
2304 	free(newkey);
2305 	sshbuf_free(b);
2306 	return r;
2307 }
2308 
2309 /* restore kex from blob for packet state de-serialization */
2310 static int
2311 kex_from_blob(struct sshbuf *m, struct kex **kexp)
2312 {
2313 	struct kex *kex;
2314 	int r;
2315 
2316 	if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2317 	    (kex->my = sshbuf_new()) == NULL ||
2318 	    (kex->peer = sshbuf_new()) == NULL) {
2319 		r = SSH_ERR_ALLOC_FAIL;
2320 		goto out;
2321 	}
2322 	if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2323 	    (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2324 	    (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
2325 	    (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2326 	    (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
2327 	    (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2328 	    (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2329 	    (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2330 	    (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2331 	    (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2332 	    (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2333 		goto out;
2334 	kex->server = 1;
2335 	kex->done = 1;
2336 	r = 0;
2337  out:
2338 	if (r != 0 || kexp == NULL) {
2339 		if (kex != NULL) {
2340 			sshbuf_free(kex->my);
2341 			sshbuf_free(kex->peer);
2342 			free(kex);
2343 		}
2344 		if (kexp != NULL)
2345 			*kexp = NULL;
2346 	} else {
2347 		*kexp = kex;
2348 	}
2349 	return r;
2350 }
2351 
2352 /*
2353  * Restore packet state from content of blob 'm' (de-serialization).
2354  * Note that 'm' will be partially consumed on parsing or any other errors.
2355  */
2356 int
2357 ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2358 {
2359 	struct session_state *state = ssh->state;
2360 	const u_char *input, *output;
2361 	size_t ilen, olen;
2362 	int r;
2363 
2364 	if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2365 	    (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2366 	    (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2367 	    (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2368 	    (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2369 	    (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2370 	    (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2371 	    (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2372 	    (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2373 	    (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2374 	    (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2375 	    (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2376 	    (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2377 		return r;
2378 	/*
2379 	 * We set the time here so that in post-auth privsep slave we
2380 	 * count from the completion of the authentication.
2381 	 */
2382 	state->rekey_time = monotime();
2383 	/* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2384 	if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2385 	    (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2386 		return r;
2387 
2388 	if ((r = ssh_packet_set_postauth(ssh)) != 0)
2389 		return r;
2390 
2391 	sshbuf_reset(state->input);
2392 	sshbuf_reset(state->output);
2393 	if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2394 	    (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2395 	    (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2396 	    (r = sshbuf_put(state->output, output, olen)) != 0)
2397 		return r;
2398 
2399 	if (sshbuf_len(m))
2400 		return SSH_ERR_INVALID_FORMAT;
2401 	debug3("%s: done", __func__);
2402 	return 0;
2403 }
2404 
2405 /* NEW API */
2406 
2407 /* put data to the outgoing packet */
2408 
2409 int
2410 sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2411 {
2412 	return sshbuf_put(ssh->state->outgoing_packet, v, len);
2413 }
2414 
2415 int
2416 sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2417 {
2418 	return sshbuf_putb(ssh->state->outgoing_packet, b);
2419 }
2420 
2421 int
2422 sshpkt_put_u8(struct ssh *ssh, u_char val)
2423 {
2424 	return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2425 }
2426 
2427 int
2428 sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2429 {
2430 	return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2431 }
2432 
2433 int
2434 sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2435 {
2436 	return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2437 }
2438 
2439 int
2440 sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2441 {
2442 	return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2443 }
2444 
2445 int
2446 sshpkt_put_cstring(struct ssh *ssh, const void *v)
2447 {
2448 	return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2449 }
2450 
2451 int
2452 sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2453 {
2454 	return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2455 }
2456 
2457 #ifdef WITH_OPENSSL
2458 #ifdef OPENSSL_HAS_ECC
2459 int
2460 sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2461 {
2462 	return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2463 }
2464 #endif /* OPENSSL_HAS_ECC */
2465 
2466 
2467 int
2468 sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2469 {
2470 	return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2471 }
2472 #endif /* WITH_OPENSSL */
2473 
2474 /* fetch data from the incoming packet */
2475 
2476 int
2477 sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2478 {
2479 	return sshbuf_get(ssh->state->incoming_packet, valp, len);
2480 }
2481 
2482 int
2483 sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2484 {
2485 	return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2486 }
2487 
2488 int
2489 sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2490 {
2491 	return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2492 }
2493 
2494 int
2495 sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2496 {
2497 	return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2498 }
2499 
2500 int
2501 sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2502 {
2503 	return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2504 }
2505 
2506 int
2507 sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2508 {
2509 	return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2510 }
2511 
2512 int
2513 sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2514 {
2515 	return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2516 }
2517 
2518 int
2519 sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2520 {
2521 	return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2522 }
2523 
2524 #ifdef WITH_OPENSSL
2525 #ifdef OPENSSL_HAS_ECC
2526 int
2527 sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2528 {
2529 	return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2530 }
2531 #endif /* OPENSSL_HAS_ECC */
2532 
2533 
2534 int
2535 sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2536 {
2537 	return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2538 }
2539 #endif /* WITH_OPENSSL */
2540 
2541 int
2542 sshpkt_get_end(struct ssh *ssh)
2543 {
2544 	if (sshbuf_len(ssh->state->incoming_packet) > 0)
2545 		return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2546 	return 0;
2547 }
2548 
2549 const u_char *
2550 sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2551 {
2552 	if (lenp != NULL)
2553 		*lenp = sshbuf_len(ssh->state->incoming_packet);
2554 	return sshbuf_ptr(ssh->state->incoming_packet);
2555 }
2556 
2557 /* start a new packet */
2558 
2559 int
2560 sshpkt_start(struct ssh *ssh, u_char type)
2561 {
2562 	u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
2563 
2564 	DBG(debug("packet_start[%d]", type));
2565 	memset(buf, 0, sizeof(buf));
2566 	buf[sizeof(buf) - 1] = type;
2567 	sshbuf_reset(ssh->state->outgoing_packet);
2568 	return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
2569 }
2570 
2571 static int
2572 ssh_packet_send_mux(struct ssh *ssh)
2573 {
2574 	struct session_state *state = ssh->state;
2575 	u_char type, *cp;
2576 	size_t len;
2577 	int r;
2578 
2579 	if (ssh->kex)
2580 		return SSH_ERR_INTERNAL_ERROR;
2581 	len = sshbuf_len(state->outgoing_packet);
2582 	if (len < 6)
2583 		return SSH_ERR_INTERNAL_ERROR;
2584 	cp = sshbuf_mutable_ptr(state->outgoing_packet);
2585 	type = cp[5];
2586 	if (ssh_packet_log_type(type))
2587 		debug3("%s: type %u", __func__, type);
2588 	/* drop everything, but the connection protocol */
2589 	if (type >= SSH2_MSG_CONNECTION_MIN &&
2590 	    type <= SSH2_MSG_CONNECTION_MAX) {
2591 		POKE_U32(cp, len - 4);
2592 		if ((r = sshbuf_putb(state->output,
2593 		    state->outgoing_packet)) != 0)
2594 			return r;
2595 		/* sshbuf_dump(state->output, stderr); */
2596 	}
2597 	sshbuf_reset(state->outgoing_packet);
2598 	return 0;
2599 }
2600 
2601 /*
2602  * 9.2.  Ignored Data Message
2603  *
2604  *   byte      SSH_MSG_IGNORE
2605  *   string    data
2606  *
2607  * All implementations MUST understand (and ignore) this message at any
2608  * time (after receiving the protocol version). No implementation is
2609  * required to send them. This message can be used as an additional
2610  * protection measure against advanced traffic analysis techniques.
2611  */
2612 int
2613 sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2614 {
2615 	u_int32_t rnd = 0;
2616 	int r;
2617 	u_int i;
2618 
2619 	if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2620 	    (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2621 		return r;
2622 	for (i = 0; i < nbytes; i++) {
2623 		if (i % 4 == 0)
2624 			rnd = arc4random();
2625 		if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2626 			return r;
2627 		rnd >>= 8;
2628 	}
2629 	return 0;
2630 }
2631 
2632 /* send it */
2633 
2634 int
2635 sshpkt_send(struct ssh *ssh)
2636 {
2637 	if (ssh->state && ssh->state->mux)
2638 		return ssh_packet_send_mux(ssh);
2639 	return ssh_packet_send2(ssh);
2640 }
2641 
2642 int
2643 sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2644 {
2645 	char buf[1024];
2646 	va_list args;
2647 	int r;
2648 
2649 	va_start(args, fmt);
2650 	vsnprintf(buf, sizeof(buf), fmt, args);
2651 	va_end(args);
2652 
2653 	if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2654 	    (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2655 	    (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2656 	    (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2657 	    (r = sshpkt_send(ssh)) != 0)
2658 		return r;
2659 	return 0;
2660 }
2661 
2662 /* roundup current message to pad bytes */
2663 int
2664 sshpkt_add_padding(struct ssh *ssh, u_char pad)
2665 {
2666 	ssh->state->extra_pad = pad;
2667 	return 0;
2668 }
2669