1/* $OpenBSD: packet.c,v 1.315 2024/05/31 08:49:35 djm 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 <sys/types.h>
41#include <sys/queue.h>
42#include <sys/socket.h>
43#include <sys/time.h>
44#include <netinet/in.h>
45#include <netinet/ip.h>
46
47#include <errno.h>
48#include <netdb.h>
49#include <stdarg.h>
50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53#include <unistd.h>
54#include <limits.h>
55#include <poll.h>
56#include <signal.h>
57#include <time.h>
58
59#ifdef WITH_ZLIB
60#include <zlib.h>
61#endif
62
63#include "xmalloc.h"
64#include "compat.h"
65#include "ssh2.h"
66#include "cipher.h"
67#include "sshkey.h"
68#include "kex.h"
69#include "digest.h"
70#include "mac.h"
71#include "log.h"
72#include "canohost.h"
73#include "misc.h"
74#include "channels.h"
75#include "ssh.h"
76#include "packet.h"
77#include "ssherr.h"
78#include "sshbuf.h"
79
80#ifdef PACKET_DEBUG
81#define DBG(x) x
82#else
83#define DBG(x)
84#endif
85
86#define PACKET_MAX_SIZE (256 * 1024)
87
88struct packet_state {
89	u_int32_t seqnr;
90	u_int32_t packets;
91	u_int64_t blocks;
92	u_int64_t bytes;
93};
94
95struct packet {
96	TAILQ_ENTRY(packet) next;
97	u_char type;
98	struct sshbuf *payload;
99};
100
101struct session_state {
102	/*
103	 * This variable contains the file descriptors used for
104	 * communicating with the other side.  connection_in is used for
105	 * reading; connection_out for writing.  These can be the same
106	 * descriptor, in which case it is assumed to be a socket.
107	 */
108	int connection_in;
109	int connection_out;
110
111	/* Protocol flags for the remote side. */
112	u_int remote_protocol_flags;
113
114	/* Encryption context for receiving data.  Only used for decryption. */
115	struct sshcipher_ctx *receive_context;
116
117	/* Encryption context for sending data.  Only used for encryption. */
118	struct sshcipher_ctx *send_context;
119
120	/* Buffer for raw input data from the socket. */
121	struct sshbuf *input;
122
123	/* Buffer for raw output data going to the socket. */
124	struct sshbuf *output;
125
126	/* Buffer for the partial outgoing packet being constructed. */
127	struct sshbuf *outgoing_packet;
128
129	/* Buffer for the incoming packet currently being processed. */
130	struct sshbuf *incoming_packet;
131
132	/* Scratch buffer for packet compression/decompression. */
133	struct sshbuf *compression_buffer;
134
135#ifdef WITH_ZLIB
136	/* Incoming/outgoing compression dictionaries */
137	z_stream compression_in_stream;
138	z_stream compression_out_stream;
139#endif
140	int compression_in_started;
141	int compression_out_started;
142	int compression_in_failures;
143	int compression_out_failures;
144
145	/* default maximum packet size */
146	u_int max_packet_size;
147
148	/* Flag indicating whether this module has been initialized. */
149	int initialized;
150
151	/* Set to true if the connection is interactive. */
152	int interactive_mode;
153
154	/* Set to true if we are the server side. */
155	int server_side;
156
157	/* Set to true if we are authenticated. */
158	int after_authentication;
159
160	int keep_alive_timeouts;
161
162	/* The maximum time that we will wait to send or receive a packet */
163	int packet_timeout_ms;
164
165	/* Session key information for Encryption and MAC */
166	struct newkeys *newkeys[MODE_MAX];
167	struct packet_state p_read, p_send;
168
169	/* Volume-based rekeying */
170	u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
171
172	/* Time-based rekeying */
173	u_int32_t rekey_interval;	/* how often in seconds */
174	time_t rekey_time;	/* time of last rekeying */
175
176	/* roundup current message to extra_pad bytes */
177	u_char extra_pad;
178
179	/* XXX discard incoming data after MAC error */
180	u_int packet_discard;
181	size_t packet_discard_mac_already;
182	struct sshmac *packet_discard_mac;
183
184	/* Used in packet_read_poll2() */
185	u_int packlen;
186
187	/* Used in packet_send2 */
188	int rekeying;
189
190	/* Used in ssh_packet_send_mux() */
191	int mux;
192
193	/* Used in packet_set_interactive */
194	int set_interactive_called;
195
196	/* Used in packet_set_maxsize */
197	int set_maxsize_called;
198
199	/* One-off warning about weak ciphers */
200	int cipher_warning_done;
201
202	/* Hook for fuzzing inbound packets */
203	ssh_packet_hook_fn *hook_in;
204	void *hook_in_ctx;
205
206	TAILQ_HEAD(, packet) outgoing;
207};
208
209struct ssh *
210ssh_alloc_session_state(void)
211{
212	struct ssh *ssh = NULL;
213	struct session_state *state = NULL;
214
215	if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
216	    (state = calloc(1, sizeof(*state))) == NULL ||
217	    (ssh->kex = kex_new()) == NULL ||
218	    (state->input = sshbuf_new()) == NULL ||
219	    (state->output = sshbuf_new()) == NULL ||
220	    (state->outgoing_packet = sshbuf_new()) == NULL ||
221	    (state->incoming_packet = sshbuf_new()) == NULL)
222		goto fail;
223	TAILQ_INIT(&state->outgoing);
224	TAILQ_INIT(&ssh->private_keys);
225	TAILQ_INIT(&ssh->public_keys);
226	state->connection_in = -1;
227	state->connection_out = -1;
228	state->max_packet_size = 32768;
229	state->packet_timeout_ms = -1;
230	state->p_send.packets = state->p_read.packets = 0;
231	state->initialized = 1;
232	/*
233	 * ssh_packet_send2() needs to queue packets until
234	 * we've done the initial key exchange.
235	 */
236	state->rekeying = 1;
237	ssh->state = state;
238	return ssh;
239 fail:
240	if (ssh) {
241		kex_free(ssh->kex);
242		free(ssh);
243	}
244	if (state) {
245		sshbuf_free(state->input);
246		sshbuf_free(state->output);
247		sshbuf_free(state->incoming_packet);
248		sshbuf_free(state->outgoing_packet);
249		free(state);
250	}
251	return NULL;
252}
253
254void
255ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
256{
257	ssh->state->hook_in = hook;
258	ssh->state->hook_in_ctx = ctx;
259}
260
261/* Returns nonzero if rekeying is in progress */
262int
263ssh_packet_is_rekeying(struct ssh *ssh)
264{
265	return ssh->state->rekeying ||
266	    (ssh->kex != NULL && ssh->kex->done == 0);
267}
268
269/*
270 * Sets the descriptors used for communication.
271 */
272struct ssh *
273ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
274{
275	struct session_state *state;
276	const struct sshcipher *none = cipher_by_name("none");
277	int r;
278
279	if (none == NULL) {
280		error_f("cannot load cipher 'none'");
281		return NULL;
282	}
283	if (ssh == NULL)
284		ssh = ssh_alloc_session_state();
285	if (ssh == NULL) {
286		error_f("could not allocate state");
287		return NULL;
288	}
289	state = ssh->state;
290	state->connection_in = fd_in;
291	state->connection_out = fd_out;
292	if ((r = cipher_init(&state->send_context, none,
293	    (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
294	    (r = cipher_init(&state->receive_context, none,
295	    (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
296		error_fr(r, "cipher_init failed");
297		free(ssh); /* XXX need ssh_free_session_state? */
298		return NULL;
299	}
300	state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
301	/*
302	 * Cache the IP address of the remote connection for use in error
303	 * messages that might be generated after the connection has closed.
304	 */
305	(void)ssh_remote_ipaddr(ssh);
306	return ssh;
307}
308
309void
310ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
311{
312	struct session_state *state = ssh->state;
313
314	if (timeout <= 0 || count <= 0) {
315		state->packet_timeout_ms = -1;
316		return;
317	}
318	if ((INT_MAX / 1000) / count < timeout)
319		state->packet_timeout_ms = INT_MAX;
320	else
321		state->packet_timeout_ms = timeout * count * 1000;
322}
323
324void
325ssh_packet_set_mux(struct ssh *ssh)
326{
327	ssh->state->mux = 1;
328	ssh->state->rekeying = 0;
329	kex_free(ssh->kex);
330	ssh->kex = NULL;
331}
332
333int
334ssh_packet_get_mux(struct ssh *ssh)
335{
336	return ssh->state->mux;
337}
338
339int
340ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
341{
342	va_list args;
343	int r;
344
345	free(ssh->log_preamble);
346	if (fmt == NULL)
347		ssh->log_preamble = NULL;
348	else {
349		va_start(args, fmt);
350		r = vasprintf(&ssh->log_preamble, fmt, args);
351		va_end(args);
352		if (r < 0 || ssh->log_preamble == NULL)
353			return SSH_ERR_ALLOC_FAIL;
354	}
355	return 0;
356}
357
358int
359ssh_packet_stop_discard(struct ssh *ssh)
360{
361	struct session_state *state = ssh->state;
362	int r;
363
364	if (state->packet_discard_mac) {
365		char buf[1024];
366		size_t dlen = PACKET_MAX_SIZE;
367
368		if (dlen > state->packet_discard_mac_already)
369			dlen -= state->packet_discard_mac_already;
370		memset(buf, 'a', sizeof(buf));
371		while (sshbuf_len(state->incoming_packet) < dlen)
372			if ((r = sshbuf_put(state->incoming_packet, buf,
373			    sizeof(buf))) != 0)
374				return r;
375		(void) mac_compute(state->packet_discard_mac,
376		    state->p_read.seqnr,
377		    sshbuf_ptr(state->incoming_packet), dlen,
378		    NULL, 0);
379	}
380	logit("Finished discarding for %.200s port %d",
381	    ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
382	return SSH_ERR_MAC_INVALID;
383}
384
385static int
386ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
387    struct sshmac *mac, size_t mac_already, u_int discard)
388{
389	struct session_state *state = ssh->state;
390	int r;
391
392	if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
393		if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
394			return r;
395		return SSH_ERR_MAC_INVALID;
396	}
397	/*
398	 * Record number of bytes over which the mac has already
399	 * been computed in order to minimize timing attacks.
400	 */
401	if (mac && mac->enabled) {
402		state->packet_discard_mac = mac;
403		state->packet_discard_mac_already = mac_already;
404	}
405	if (sshbuf_len(state->input) >= discard)
406		return ssh_packet_stop_discard(ssh);
407	state->packet_discard = discard - sshbuf_len(state->input);
408	return 0;
409}
410
411/* Returns 1 if remote host is connected via socket, 0 if not. */
412
413int
414ssh_packet_connection_is_on_socket(struct ssh *ssh)
415{
416	struct session_state *state;
417	struct sockaddr_storage from, to;
418	socklen_t fromlen, tolen;
419
420	if (ssh == NULL || ssh->state == NULL)
421		return 0;
422
423	state = ssh->state;
424	if (state->connection_in == -1 || state->connection_out == -1)
425		return 0;
426	/* filedescriptors in and out are the same, so it's a socket */
427	if (state->connection_in == state->connection_out)
428		return 1;
429	fromlen = sizeof(from);
430	memset(&from, 0, sizeof(from));
431	if (getpeername(state->connection_in, (struct sockaddr *)&from,
432	    &fromlen) == -1)
433		return 0;
434	tolen = sizeof(to);
435	memset(&to, 0, sizeof(to));
436	if (getpeername(state->connection_out, (struct sockaddr *)&to,
437	    &tolen) == -1)
438		return 0;
439	if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
440		return 0;
441	if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
442		return 0;
443	return 1;
444}
445
446void
447ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
448{
449	if (ibytes)
450		*ibytes = ssh->state->p_read.bytes;
451	if (obytes)
452		*obytes = ssh->state->p_send.bytes;
453}
454
455int
456ssh_packet_connection_af(struct ssh *ssh)
457{
458	return get_sock_af(ssh->state->connection_out);
459}
460
461/* Sets the connection into non-blocking mode. */
462
463void
464ssh_packet_set_nonblocking(struct ssh *ssh)
465{
466	/* Set the socket into non-blocking mode. */
467	set_nonblock(ssh->state->connection_in);
468
469	if (ssh->state->connection_out != ssh->state->connection_in)
470		set_nonblock(ssh->state->connection_out);
471}
472
473/* Returns the socket used for reading. */
474
475int
476ssh_packet_get_connection_in(struct ssh *ssh)
477{
478	return ssh->state->connection_in;
479}
480
481/* Returns the descriptor used for writing. */
482
483int
484ssh_packet_get_connection_out(struct ssh *ssh)
485{
486	return ssh->state->connection_out;
487}
488
489/*
490 * Returns the IP-address of the remote host as a string.  The returned
491 * string must not be freed.
492 */
493
494const char *
495ssh_remote_ipaddr(struct ssh *ssh)
496{
497	int sock;
498
499	/* Check whether we have cached the ipaddr. */
500	if (ssh->remote_ipaddr == NULL) {
501		if (ssh_packet_connection_is_on_socket(ssh)) {
502			sock = ssh->state->connection_in;
503			ssh->remote_ipaddr = get_peer_ipaddr(sock);
504			ssh->remote_port = get_peer_port(sock);
505			ssh->local_ipaddr = get_local_ipaddr(sock);
506			ssh->local_port = get_local_port(sock);
507		} else {
508			ssh->remote_ipaddr = xstrdup("UNKNOWN");
509			ssh->remote_port = 65535;
510			ssh->local_ipaddr = xstrdup("UNKNOWN");
511			ssh->local_port = 65535;
512		}
513	}
514	return ssh->remote_ipaddr;
515}
516
517/*
518 * Returns the remote DNS hostname as a string. The returned string must not
519 * be freed. NB. this will usually trigger a DNS query. Return value is on
520 * heap and no caching is performed.
521 * This function does additional checks on the hostname to mitigate some
522 * attacks based on conflation of hostnames and addresses and will
523 * fall back to returning an address on error.
524 */
525
526char *
527ssh_remote_hostname(struct ssh *ssh)
528{
529	struct sockaddr_storage from;
530	socklen_t fromlen;
531	struct addrinfo hints, *ai, *aitop;
532	char name[NI_MAXHOST], ntop2[NI_MAXHOST];
533	const char *ntop = ssh_remote_ipaddr(ssh);
534
535	/* Get IP address of client. */
536	fromlen = sizeof(from);
537	memset(&from, 0, sizeof(from));
538	if (getpeername(ssh_packet_get_connection_in(ssh),
539	    (struct sockaddr *)&from, &fromlen) == -1) {
540		debug_f("getpeername failed: %.100s", strerror(errno));
541		return xstrdup(ntop);
542	}
543
544	debug3_f("trying to reverse map address %.100s.", ntop);
545	/* Map the IP address to a host name. */
546	if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name),
547	    NULL, 0, NI_NAMEREQD) != 0) {
548		/* Host name not found.  Use ip address. */
549		return xstrdup(ntop);
550	}
551
552	/*
553	 * if reverse lookup result looks like a numeric hostname,
554	 * someone is trying to trick us by PTR record like following:
555	 *	1.1.1.10.in-addr.arpa.	IN PTR	2.3.4.5
556	 */
557	memset(&hints, 0, sizeof(hints));
558	hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
559	hints.ai_flags = AI_NUMERICHOST;
560	if (getaddrinfo(name, NULL, &hints, &ai) == 0) {
561		logit("Nasty PTR record \"%s\" is set up for %s, ignoring",
562		    name, ntop);
563		freeaddrinfo(ai);
564		return xstrdup(ntop);
565	}
566
567	/* Names are stored in lowercase. */
568	lowercase(name);
569
570	/*
571	 * Map it back to an IP address and check that the given
572	 * address actually is an address of this host.  This is
573	 * necessary because anyone with access to a name server can
574	 * define arbitrary names for an IP address. Mapping from
575	 * name to IP address can be trusted better (but can still be
576	 * fooled if the intruder has access to the name server of
577	 * the domain).
578	 */
579	memset(&hints, 0, sizeof(hints));
580	hints.ai_family = from.ss_family;
581	hints.ai_socktype = SOCK_STREAM;
582	if (getaddrinfo(name, NULL, &hints, &aitop) != 0) {
583		logit("reverse mapping checking getaddrinfo for %.700s "
584		    "[%s] failed.", name, ntop);
585		return xstrdup(ntop);
586	}
587	/* Look for the address from the list of addresses. */
588	for (ai = aitop; ai; ai = ai->ai_next) {
589		if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2,
590		    sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 &&
591		    (strcmp(ntop, ntop2) == 0))
592				break;
593	}
594	freeaddrinfo(aitop);
595	/* If we reached the end of the list, the address was not there. */
596	if (ai == NULL) {
597		/* Address not found for the host name. */
598		logit("Address %.100s maps to %.600s, but this does not "
599		    "map back to the address.", ntop, name);
600		return xstrdup(ntop);
601	}
602	return xstrdup(name);
603}
604
605/* Returns the port number of the remote host. */
606
607int
608ssh_remote_port(struct ssh *ssh)
609{
610	(void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
611	return ssh->remote_port;
612}
613
614/*
615 * Returns the IP-address of the local host as a string.  The returned
616 * string must not be freed.
617 */
618
619const char *
620ssh_local_ipaddr(struct ssh *ssh)
621{
622	(void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
623	return ssh->local_ipaddr;
624}
625
626/* Returns the port number of the local host. */
627
628int
629ssh_local_port(struct ssh *ssh)
630{
631	(void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
632	return ssh->local_port;
633}
634
635/* Returns the routing domain of the input socket, or NULL if unavailable */
636const char *
637ssh_packet_rdomain_in(struct ssh *ssh)
638{
639	if (ssh->rdomain_in != NULL)
640		return ssh->rdomain_in;
641	if (!ssh_packet_connection_is_on_socket(ssh))
642		return NULL;
643	ssh->rdomain_in = get_rdomain(ssh->state->connection_in);
644	return ssh->rdomain_in;
645}
646
647/* Closes the connection and clears and frees internal data structures. */
648
649static void
650ssh_packet_close_internal(struct ssh *ssh, int do_close)
651{
652	struct session_state *state = ssh->state;
653	u_int mode;
654
655	if (!state->initialized)
656		return;
657	state->initialized = 0;
658	if (do_close) {
659		if (state->connection_in == state->connection_out) {
660			close(state->connection_out);
661		} else {
662			close(state->connection_in);
663			close(state->connection_out);
664		}
665	}
666	sshbuf_free(state->input);
667	sshbuf_free(state->output);
668	sshbuf_free(state->outgoing_packet);
669	sshbuf_free(state->incoming_packet);
670	for (mode = 0; mode < MODE_MAX; mode++) {
671		kex_free_newkeys(state->newkeys[mode]);	/* current keys */
672		state->newkeys[mode] = NULL;
673		ssh_clear_newkeys(ssh, mode);		/* next keys */
674	}
675#ifdef WITH_ZLIB
676	/* compression state is in shared mem, so we can only release it once */
677	if (do_close && state->compression_buffer) {
678		sshbuf_free(state->compression_buffer);
679		if (state->compression_out_started) {
680			z_streamp stream = &state->compression_out_stream;
681			debug("compress outgoing: "
682			    "raw data %llu, compressed %llu, factor %.2f",
683				(unsigned long long)stream->total_in,
684				(unsigned long long)stream->total_out,
685				stream->total_in == 0 ? 0.0 :
686				(double) stream->total_out / stream->total_in);
687			if (state->compression_out_failures == 0)
688				deflateEnd(stream);
689		}
690		if (state->compression_in_started) {
691			z_streamp stream = &state->compression_in_stream;
692			debug("compress incoming: "
693			    "raw data %llu, compressed %llu, factor %.2f",
694			    (unsigned long long)stream->total_out,
695			    (unsigned long long)stream->total_in,
696			    stream->total_out == 0 ? 0.0 :
697			    (double) stream->total_in / stream->total_out);
698			if (state->compression_in_failures == 0)
699				inflateEnd(stream);
700		}
701	}
702#endif	/* WITH_ZLIB */
703	cipher_free(state->send_context);
704	cipher_free(state->receive_context);
705	state->send_context = state->receive_context = NULL;
706	if (do_close) {
707		free(ssh->local_ipaddr);
708		ssh->local_ipaddr = NULL;
709		free(ssh->remote_ipaddr);
710		ssh->remote_ipaddr = NULL;
711		free(ssh->state);
712		ssh->state = NULL;
713		kex_free(ssh->kex);
714		ssh->kex = NULL;
715	}
716}
717
718void
719ssh_packet_close(struct ssh *ssh)
720{
721	ssh_packet_close_internal(ssh, 1);
722}
723
724void
725ssh_packet_clear_keys(struct ssh *ssh)
726{
727	ssh_packet_close_internal(ssh, 0);
728}
729
730/* Sets remote side protocol flags. */
731
732void
733ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
734{
735	ssh->state->remote_protocol_flags = protocol_flags;
736}
737
738/* Returns the remote protocol flags set earlier by the above function. */
739
740u_int
741ssh_packet_get_protocol_flags(struct ssh *ssh)
742{
743	return ssh->state->remote_protocol_flags;
744}
745
746/*
747 * Starts packet compression from the next packet on in both directions.
748 * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
749 */
750
751static int
752ssh_packet_init_compression(struct ssh *ssh)
753{
754	if (!ssh->state->compression_buffer &&
755	    ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
756		return SSH_ERR_ALLOC_FAIL;
757	return 0;
758}
759
760#ifdef WITH_ZLIB
761static int
762start_compression_out(struct ssh *ssh, int level)
763{
764	if (level < 1 || level > 9)
765		return SSH_ERR_INVALID_ARGUMENT;
766	debug("Enabling compression at level %d.", level);
767	if (ssh->state->compression_out_started == 1)
768		deflateEnd(&ssh->state->compression_out_stream);
769	switch (deflateInit(&ssh->state->compression_out_stream, level)) {
770	case Z_OK:
771		ssh->state->compression_out_started = 1;
772		break;
773	case Z_MEM_ERROR:
774		return SSH_ERR_ALLOC_FAIL;
775	default:
776		return SSH_ERR_INTERNAL_ERROR;
777	}
778	return 0;
779}
780
781static int
782start_compression_in(struct ssh *ssh)
783{
784	if (ssh->state->compression_in_started == 1)
785		inflateEnd(&ssh->state->compression_in_stream);
786	switch (inflateInit(&ssh->state->compression_in_stream)) {
787	case Z_OK:
788		ssh->state->compression_in_started = 1;
789		break;
790	case Z_MEM_ERROR:
791		return SSH_ERR_ALLOC_FAIL;
792	default:
793		return SSH_ERR_INTERNAL_ERROR;
794	}
795	return 0;
796}
797
798/* XXX remove need for separate compression buffer */
799static int
800compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
801{
802	u_char buf[4096];
803	int r, status;
804
805	if (ssh->state->compression_out_started != 1)
806		return SSH_ERR_INTERNAL_ERROR;
807
808	/* This case is not handled below. */
809	if (sshbuf_len(in) == 0)
810		return 0;
811
812	/* Input is the contents of the input buffer. */
813	if ((ssh->state->compression_out_stream.next_in =
814	    sshbuf_mutable_ptr(in)) == NULL)
815		return SSH_ERR_INTERNAL_ERROR;
816	ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
817
818	/* Loop compressing until deflate() returns with avail_out != 0. */
819	do {
820		/* Set up fixed-size output buffer. */
821		ssh->state->compression_out_stream.next_out = buf;
822		ssh->state->compression_out_stream.avail_out = sizeof(buf);
823
824		/* Compress as much data into the buffer as possible. */
825		status = deflate(&ssh->state->compression_out_stream,
826		    Z_PARTIAL_FLUSH);
827		switch (status) {
828		case Z_MEM_ERROR:
829			return SSH_ERR_ALLOC_FAIL;
830		case Z_OK:
831			/* Append compressed data to output_buffer. */
832			if ((r = sshbuf_put(out, buf, sizeof(buf) -
833			    ssh->state->compression_out_stream.avail_out)) != 0)
834				return r;
835			break;
836		case Z_STREAM_ERROR:
837		default:
838			ssh->state->compression_out_failures++;
839			return SSH_ERR_INVALID_FORMAT;
840		}
841	} while (ssh->state->compression_out_stream.avail_out == 0);
842	return 0;
843}
844
845static int
846uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
847{
848	u_char buf[4096];
849	int r, status;
850
851	if (ssh->state->compression_in_started != 1)
852		return SSH_ERR_INTERNAL_ERROR;
853
854	if ((ssh->state->compression_in_stream.next_in =
855	    sshbuf_mutable_ptr(in)) == NULL)
856		return SSH_ERR_INTERNAL_ERROR;
857	ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
858
859	for (;;) {
860		/* Set up fixed-size output buffer. */
861		ssh->state->compression_in_stream.next_out = buf;
862		ssh->state->compression_in_stream.avail_out = sizeof(buf);
863
864		status = inflate(&ssh->state->compression_in_stream,
865		    Z_SYNC_FLUSH);
866		switch (status) {
867		case Z_OK:
868			if ((r = sshbuf_put(out, buf, sizeof(buf) -
869			    ssh->state->compression_in_stream.avail_out)) != 0)
870				return r;
871			break;
872		case Z_BUF_ERROR:
873			/*
874			 * Comments in zlib.h say that we should keep calling
875			 * inflate() until we get an error.  This appears to
876			 * be the error that we get.
877			 */
878			return 0;
879		case Z_DATA_ERROR:
880			return SSH_ERR_INVALID_FORMAT;
881		case Z_MEM_ERROR:
882			return SSH_ERR_ALLOC_FAIL;
883		case Z_STREAM_ERROR:
884		default:
885			ssh->state->compression_in_failures++;
886			return SSH_ERR_INTERNAL_ERROR;
887		}
888	}
889	/* NOTREACHED */
890}
891
892#else	/* WITH_ZLIB */
893
894static int
895start_compression_out(struct ssh *ssh, int level)
896{
897	return SSH_ERR_INTERNAL_ERROR;
898}
899
900static int
901start_compression_in(struct ssh *ssh)
902{
903	return SSH_ERR_INTERNAL_ERROR;
904}
905
906static int
907compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
908{
909	return SSH_ERR_INTERNAL_ERROR;
910}
911
912static int
913uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
914{
915	return SSH_ERR_INTERNAL_ERROR;
916}
917#endif	/* WITH_ZLIB */
918
919void
920ssh_clear_newkeys(struct ssh *ssh, int mode)
921{
922	if (ssh->kex && ssh->kex->newkeys[mode]) {
923		kex_free_newkeys(ssh->kex->newkeys[mode]);
924		ssh->kex->newkeys[mode] = NULL;
925	}
926}
927
928int
929ssh_set_newkeys(struct ssh *ssh, int mode)
930{
931	struct session_state *state = ssh->state;
932	struct sshenc *enc;
933	struct sshmac *mac;
934	struct sshcomp *comp;
935	struct sshcipher_ctx **ccp;
936	struct packet_state *ps;
937	u_int64_t *max_blocks;
938	const char *wmsg;
939	int r, crypt_type;
940	const char *dir = mode == MODE_OUT ? "out" : "in";
941
942	debug2_f("mode %d", mode);
943
944	if (mode == MODE_OUT) {
945		ccp = &state->send_context;
946		crypt_type = CIPHER_ENCRYPT;
947		ps = &state->p_send;
948		max_blocks = &state->max_blocks_out;
949	} else {
950		ccp = &state->receive_context;
951		crypt_type = CIPHER_DECRYPT;
952		ps = &state->p_read;
953		max_blocks = &state->max_blocks_in;
954	}
955	if (state->newkeys[mode] != NULL) {
956		debug_f("rekeying %s, input %llu bytes %llu blocks, "
957		    "output %llu bytes %llu blocks", dir,
958		    (unsigned long long)state->p_read.bytes,
959		    (unsigned long long)state->p_read.blocks,
960		    (unsigned long long)state->p_send.bytes,
961		    (unsigned long long)state->p_send.blocks);
962		kex_free_newkeys(state->newkeys[mode]);
963		state->newkeys[mode] = NULL;
964	}
965	/* note that both bytes and the seqnr are not reset */
966	ps->packets = ps->blocks = 0;
967	/* move newkeys from kex to state */
968	if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
969		return SSH_ERR_INTERNAL_ERROR;
970	ssh->kex->newkeys[mode] = NULL;
971	enc  = &state->newkeys[mode]->enc;
972	mac  = &state->newkeys[mode]->mac;
973	comp = &state->newkeys[mode]->comp;
974	if (cipher_authlen(enc->cipher) == 0) {
975		if ((r = mac_init(mac)) != 0)
976			return r;
977	}
978	mac->enabled = 1;
979	DBG(debug_f("cipher_init: %s", dir));
980	cipher_free(*ccp);
981	*ccp = NULL;
982	if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
983	    enc->iv, enc->iv_len, crypt_type)) != 0)
984		return r;
985	if (!state->cipher_warning_done &&
986	    (wmsg = cipher_warning_message(*ccp)) != NULL) {
987		error("Warning: %s", wmsg);
988		state->cipher_warning_done = 1;
989	}
990	/* Deleting the keys does not gain extra security */
991	/* explicit_bzero(enc->iv,  enc->block_size);
992	   explicit_bzero(enc->key, enc->key_len);
993	   explicit_bzero(mac->key, mac->key_len); */
994	if ((comp->type == COMP_ZLIB ||
995	    (comp->type == COMP_DELAYED &&
996	    state->after_authentication)) && comp->enabled == 0) {
997		if ((r = ssh_packet_init_compression(ssh)) < 0)
998			return r;
999		if (mode == MODE_OUT) {
1000			if ((r = start_compression_out(ssh, 6)) != 0)
1001				return r;
1002		} else {
1003			if ((r = start_compression_in(ssh)) != 0)
1004				return r;
1005		}
1006		comp->enabled = 1;
1007	}
1008	/*
1009	 * The 2^(blocksize*2) limit is too expensive for 3DES,
1010	 * so enforce a 1GB limit for small blocksizes.
1011	 * See RFC4344 section 3.2.
1012	 */
1013	if (enc->block_size >= 16)
1014		*max_blocks = (u_int64_t)1 << (enc->block_size*2);
1015	else
1016		*max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1017	if (state->rekey_limit)
1018		*max_blocks = MINIMUM(*max_blocks,
1019		    state->rekey_limit / enc->block_size);
1020	debug("rekey %s after %llu blocks", dir,
1021	    (unsigned long long)*max_blocks);
1022	return 0;
1023}
1024
1025#define MAX_PACKETS	(1U<<31)
1026static int
1027ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
1028{
1029	struct session_state *state = ssh->state;
1030	u_int32_t out_blocks;
1031
1032	/* XXX client can't cope with rekeying pre-auth */
1033	if (!state->after_authentication)
1034		return 0;
1035
1036	/* Haven't keyed yet or KEX in progress. */
1037	if (ssh_packet_is_rekeying(ssh))
1038		return 0;
1039
1040	/* Peer can't rekey */
1041	if (ssh->compat & SSH_BUG_NOREKEY)
1042		return 0;
1043
1044	/*
1045	 * Permit one packet in or out per rekey - this allows us to
1046	 * make progress when rekey limits are very small.
1047	 */
1048	if (state->p_send.packets == 0 && state->p_read.packets == 0)
1049		return 0;
1050
1051	/* Time-based rekeying */
1052	if (state->rekey_interval != 0 &&
1053	    (int64_t)state->rekey_time + state->rekey_interval <= monotime())
1054		return 1;
1055
1056	/*
1057	 * Always rekey when MAX_PACKETS sent in either direction
1058	 * As per RFC4344 section 3.1 we do this after 2^31 packets.
1059	 */
1060	if (state->p_send.packets > MAX_PACKETS ||
1061	    state->p_read.packets > MAX_PACKETS)
1062		return 1;
1063
1064	/* Rekey after (cipher-specific) maximum blocks */
1065	out_blocks = ROUNDUP(outbound_packet_len,
1066	    state->newkeys[MODE_OUT]->enc.block_size);
1067	return (state->max_blocks_out &&
1068	    (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
1069	    (state->max_blocks_in &&
1070	    (state->p_read.blocks > state->max_blocks_in));
1071}
1072
1073int
1074ssh_packet_check_rekey(struct ssh *ssh)
1075{
1076	if (!ssh_packet_need_rekeying(ssh, 0))
1077		return 0;
1078	debug3_f("rekex triggered");
1079	return kex_start_rekex(ssh);
1080}
1081
1082/*
1083 * Delayed compression for SSH2 is enabled after authentication:
1084 * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1085 * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
1086 */
1087static int
1088ssh_packet_enable_delayed_compress(struct ssh *ssh)
1089{
1090	struct session_state *state = ssh->state;
1091	struct sshcomp *comp = NULL;
1092	int r, mode;
1093
1094	/*
1095	 * Remember that we are past the authentication step, so rekeying
1096	 * with COMP_DELAYED will turn on compression immediately.
1097	 */
1098	state->after_authentication = 1;
1099	for (mode = 0; mode < MODE_MAX; mode++) {
1100		/* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1101		if (state->newkeys[mode] == NULL)
1102			continue;
1103		comp = &state->newkeys[mode]->comp;
1104		if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1105			if ((r = ssh_packet_init_compression(ssh)) != 0)
1106				return r;
1107			if (mode == MODE_OUT) {
1108				if ((r = start_compression_out(ssh, 6)) != 0)
1109					return r;
1110			} else {
1111				if ((r = start_compression_in(ssh)) != 0)
1112					return r;
1113			}
1114			comp->enabled = 1;
1115		}
1116	}
1117	return 0;
1118}
1119
1120/* Used to mute debug logging for noisy packet types */
1121int
1122ssh_packet_log_type(u_char type)
1123{
1124	switch (type) {
1125	case SSH2_MSG_PING:
1126	case SSH2_MSG_PONG:
1127	case SSH2_MSG_CHANNEL_DATA:
1128	case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1129	case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1130		return 0;
1131	default:
1132		return 1;
1133	}
1134}
1135
1136/*
1137 * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1138 */
1139int
1140ssh_packet_send2_wrapped(struct ssh *ssh)
1141{
1142	struct session_state *state = ssh->state;
1143	u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1144	u_char tmp, padlen, pad = 0;
1145	u_int authlen = 0, aadlen = 0;
1146	u_int len;
1147	struct sshenc *enc   = NULL;
1148	struct sshmac *mac   = NULL;
1149	struct sshcomp *comp = NULL;
1150	int r, block_size;
1151
1152	if (state->newkeys[MODE_OUT] != NULL) {
1153		enc  = &state->newkeys[MODE_OUT]->enc;
1154		mac  = &state->newkeys[MODE_OUT]->mac;
1155		comp = &state->newkeys[MODE_OUT]->comp;
1156		/* disable mac for authenticated encryption */
1157		if ((authlen = cipher_authlen(enc->cipher)) != 0)
1158			mac = NULL;
1159	}
1160	block_size = enc ? enc->block_size : 8;
1161	aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1162
1163	type = (sshbuf_ptr(state->outgoing_packet))[5];
1164	if (ssh_packet_log_type(type))
1165		debug3("send packet: type %u", type);
1166#ifdef PACKET_DEBUG
1167	fprintf(stderr, "plain:     ");
1168	sshbuf_dump(state->outgoing_packet, stderr);
1169#endif
1170
1171	if (comp && comp->enabled) {
1172		len = sshbuf_len(state->outgoing_packet);
1173		/* skip header, compress only payload */
1174		if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1175			goto out;
1176		sshbuf_reset(state->compression_buffer);
1177		if ((r = compress_buffer(ssh, state->outgoing_packet,
1178		    state->compression_buffer)) != 0)
1179			goto out;
1180		sshbuf_reset(state->outgoing_packet);
1181		if ((r = sshbuf_put(state->outgoing_packet,
1182		    "\0\0\0\0\0", 5)) != 0 ||
1183		    (r = sshbuf_putb(state->outgoing_packet,
1184		    state->compression_buffer)) != 0)
1185			goto out;
1186		DBG(debug("compression: raw %d compressed %zd", len,
1187		    sshbuf_len(state->outgoing_packet)));
1188	}
1189
1190	/* sizeof (packet_len + pad_len + payload) */
1191	len = sshbuf_len(state->outgoing_packet);
1192
1193	/*
1194	 * calc size of padding, alloc space, get random data,
1195	 * minimum padding is 4 bytes
1196	 */
1197	len -= aadlen; /* packet length is not encrypted for EtM modes */
1198	padlen = block_size - (len % block_size);
1199	if (padlen < 4)
1200		padlen += block_size;
1201	if (state->extra_pad) {
1202		tmp = state->extra_pad;
1203		state->extra_pad =
1204		    ROUNDUP(state->extra_pad, block_size);
1205		/* check if roundup overflowed */
1206		if (state->extra_pad < tmp)
1207			return SSH_ERR_INVALID_ARGUMENT;
1208		tmp = (len + padlen) % state->extra_pad;
1209		/* Check whether pad calculation below will underflow */
1210		if (tmp > state->extra_pad)
1211			return SSH_ERR_INVALID_ARGUMENT;
1212		pad = state->extra_pad - tmp;
1213		DBG(debug3_f("adding %d (len %d padlen %d extra_pad %d)",
1214		    pad, len, padlen, state->extra_pad));
1215		tmp = padlen;
1216		padlen += pad;
1217		/* Check whether padlen calculation overflowed */
1218		if (padlen < tmp)
1219			return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1220		state->extra_pad = 0;
1221	}
1222	if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1223		goto out;
1224	if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1225		/* random padding */
1226		arc4random_buf(cp, padlen);
1227	} else {
1228		/* clear padding */
1229		explicit_bzero(cp, padlen);
1230	}
1231	/* sizeof (packet_len + pad_len + payload + padding) */
1232	len = sshbuf_len(state->outgoing_packet);
1233	cp = sshbuf_mutable_ptr(state->outgoing_packet);
1234	if (cp == NULL) {
1235		r = SSH_ERR_INTERNAL_ERROR;
1236		goto out;
1237	}
1238	/* packet_length includes payload, padding and padding length field */
1239	POKE_U32(cp, len - 4);
1240	cp[4] = padlen;
1241	DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1242	    len, padlen, aadlen));
1243
1244	/* compute MAC over seqnr and packet(length fields, payload, padding) */
1245	if (mac && mac->enabled && !mac->etm) {
1246		if ((r = mac_compute(mac, state->p_send.seqnr,
1247		    sshbuf_ptr(state->outgoing_packet), len,
1248		    macbuf, sizeof(macbuf))) != 0)
1249			goto out;
1250		DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1251	}
1252	/* encrypt packet and append to output buffer. */
1253	if ((r = sshbuf_reserve(state->output,
1254	    sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1255		goto out;
1256	if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1257	    sshbuf_ptr(state->outgoing_packet),
1258	    len - aadlen, aadlen, authlen)) != 0)
1259		goto out;
1260	/* append unencrypted MAC */
1261	if (mac && mac->enabled) {
1262		if (mac->etm) {
1263			/* EtM: compute mac over aadlen + cipher text */
1264			if ((r = mac_compute(mac, state->p_send.seqnr,
1265			    cp, len, macbuf, sizeof(macbuf))) != 0)
1266				goto out;
1267			DBG(debug("done calc MAC(EtM) out #%d",
1268			    state->p_send.seqnr));
1269		}
1270		if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1271			goto out;
1272	}
1273#ifdef PACKET_DEBUG
1274	fprintf(stderr, "encrypted: ");
1275	sshbuf_dump(state->output, stderr);
1276#endif
1277	/* increment sequence number for outgoing packets */
1278	if (++state->p_send.seqnr == 0) {
1279		if ((ssh->kex->flags & KEX_INITIAL) != 0) {
1280			ssh_packet_disconnect(ssh, "outgoing sequence number "
1281			    "wrapped during initial key exchange");
1282		}
1283		logit("outgoing seqnr wraps around");
1284	}
1285	if (++state->p_send.packets == 0)
1286		if (!(ssh->compat & SSH_BUG_NOREKEY))
1287			return SSH_ERR_NEED_REKEY;
1288	state->p_send.blocks += len / block_size;
1289	state->p_send.bytes += len;
1290	sshbuf_reset(state->outgoing_packet);
1291
1292	if (type == SSH2_MSG_NEWKEYS && ssh->kex->kex_strict) {
1293		debug_f("resetting send seqnr %u", state->p_send.seqnr);
1294		state->p_send.seqnr = 0;
1295	}
1296
1297	if (type == SSH2_MSG_NEWKEYS)
1298		r = ssh_set_newkeys(ssh, MODE_OUT);
1299	else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1300		r = ssh_packet_enable_delayed_compress(ssh);
1301	else
1302		r = 0;
1303 out:
1304	return r;
1305}
1306
1307/* returns non-zero if the specified packet type is usec by KEX */
1308static int
1309ssh_packet_type_is_kex(u_char type)
1310{
1311	return
1312	    type >= SSH2_MSG_TRANSPORT_MIN &&
1313	    type <= SSH2_MSG_TRANSPORT_MAX &&
1314	    type != SSH2_MSG_SERVICE_REQUEST &&
1315	    type != SSH2_MSG_SERVICE_ACCEPT &&
1316	    type != SSH2_MSG_EXT_INFO;
1317}
1318
1319int
1320ssh_packet_send2(struct ssh *ssh)
1321{
1322	struct session_state *state = ssh->state;
1323	struct packet *p;
1324	u_char type;
1325	int r, need_rekey;
1326
1327	if (sshbuf_len(state->outgoing_packet) < 6)
1328		return SSH_ERR_INTERNAL_ERROR;
1329	type = sshbuf_ptr(state->outgoing_packet)[5];
1330	need_rekey = !ssh_packet_type_is_kex(type) &&
1331	    ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1332
1333	/*
1334	 * During rekeying we can only send key exchange messages.
1335	 * Queue everything else.
1336	 */
1337	if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1338		if (need_rekey)
1339			debug3_f("rekex triggered");
1340		debug("enqueue packet: %u", type);
1341		p = calloc(1, sizeof(*p));
1342		if (p == NULL)
1343			return SSH_ERR_ALLOC_FAIL;
1344		p->type = type;
1345		p->payload = state->outgoing_packet;
1346		TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1347		state->outgoing_packet = sshbuf_new();
1348		if (state->outgoing_packet == NULL)
1349			return SSH_ERR_ALLOC_FAIL;
1350		if (need_rekey) {
1351			/*
1352			 * This packet triggered a rekey, so send the
1353			 * KEXINIT now.
1354			 * NB. reenters this function via kex_start_rekex().
1355			 */
1356			return kex_start_rekex(ssh);
1357		}
1358		return 0;
1359	}
1360
1361	/* rekeying starts with sending KEXINIT */
1362	if (type == SSH2_MSG_KEXINIT)
1363		state->rekeying = 1;
1364
1365	if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1366		return r;
1367
1368	/* after a NEWKEYS message we can send the complete queue */
1369	if (type == SSH2_MSG_NEWKEYS) {
1370		state->rekeying = 0;
1371		state->rekey_time = monotime();
1372		while ((p = TAILQ_FIRST(&state->outgoing))) {
1373			type = p->type;
1374			/*
1375			 * If this packet triggers a rekex, then skip the
1376			 * remaining packets in the queue for now.
1377			 * NB. re-enters this function via kex_start_rekex.
1378			 */
1379			if (ssh_packet_need_rekeying(ssh,
1380			    sshbuf_len(p->payload))) {
1381				debug3_f("queued packet triggered rekex");
1382				return kex_start_rekex(ssh);
1383			}
1384			debug("dequeue packet: %u", type);
1385			sshbuf_free(state->outgoing_packet);
1386			state->outgoing_packet = p->payload;
1387			TAILQ_REMOVE(&state->outgoing, p, next);
1388			memset(p, 0, sizeof(*p));
1389			free(p);
1390			if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1391				return r;
1392		}
1393	}
1394	return 0;
1395}
1396
1397/*
1398 * Waits until a packet has been received, and returns its type.  Note that
1399 * no other data is processed until this returns, so this function should not
1400 * be used during the interactive session.
1401 */
1402
1403int
1404ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1405{
1406	struct session_state *state = ssh->state;
1407	int len, r, ms_remain = 0;
1408	struct pollfd pfd;
1409	char buf[8192];
1410	struct timeval start;
1411	struct timespec timespec, *timespecp = NULL;
1412
1413	DBG(debug("packet_read()"));
1414
1415	/*
1416	 * Since we are blocking, ensure that all written packets have
1417	 * been sent.
1418	 */
1419	if ((r = ssh_packet_write_wait(ssh)) != 0)
1420		goto out;
1421
1422	/* Stay in the loop until we have received a complete packet. */
1423	for (;;) {
1424		/* Try to read a packet from the buffer. */
1425		if ((r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p)) != 0)
1426			break;
1427		/* If we got a packet, return it. */
1428		if (*typep != SSH_MSG_NONE)
1429			break;
1430		/*
1431		 * Otherwise, wait for some data to arrive, add it to the
1432		 * buffer, and try again.
1433		 */
1434		pfd.fd = state->connection_in;
1435		pfd.events = POLLIN;
1436
1437		if (state->packet_timeout_ms > 0) {
1438			ms_remain = state->packet_timeout_ms;
1439			timespecp = &timespec;
1440		}
1441		/* Wait for some data to arrive. */
1442		for (;;) {
1443			if (state->packet_timeout_ms > 0) {
1444				ms_to_timespec(&timespec, ms_remain);
1445				monotime_tv(&start);
1446			}
1447			if ((r = ppoll(&pfd, 1, timespecp, NULL)) >= 0)
1448				break;
1449			if (errno != EAGAIN && errno != EINTR) {
1450				r = SSH_ERR_SYSTEM_ERROR;
1451				goto out;
1452			}
1453			if (state->packet_timeout_ms <= 0)
1454				continue;
1455			ms_subtract_diff(&start, &ms_remain);
1456			if (ms_remain <= 0) {
1457				r = 0;
1458				break;
1459			}
1460		}
1461		if (r == 0) {
1462			r = SSH_ERR_CONN_TIMEOUT;
1463			goto out;
1464		}
1465		/* Read data from the socket. */
1466		len = read(state->connection_in, buf, sizeof(buf));
1467		if (len == 0) {
1468			r = SSH_ERR_CONN_CLOSED;
1469			goto out;
1470		}
1471		if (len == -1) {
1472			r = SSH_ERR_SYSTEM_ERROR;
1473			goto out;
1474		}
1475
1476		/* Append it to the buffer. */
1477		if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1478			goto out;
1479	}
1480 out:
1481	return r;
1482}
1483
1484int
1485ssh_packet_read(struct ssh *ssh)
1486{
1487	u_char type;
1488	int r;
1489
1490	if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1491		fatal_fr(r, "read");
1492	return type;
1493}
1494
1495static int
1496ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1497{
1498	struct session_state *state = ssh->state;
1499	const u_char *cp;
1500	size_t need;
1501	int r;
1502
1503	if (ssh->kex)
1504		return SSH_ERR_INTERNAL_ERROR;
1505	*typep = SSH_MSG_NONE;
1506	cp = sshbuf_ptr(state->input);
1507	if (state->packlen == 0) {
1508		if (sshbuf_len(state->input) < 4 + 1)
1509			return 0; /* packet is incomplete */
1510		state->packlen = PEEK_U32(cp);
1511		if (state->packlen < 4 + 1 ||
1512		    state->packlen > PACKET_MAX_SIZE)
1513			return SSH_ERR_MESSAGE_INCOMPLETE;
1514	}
1515	need = state->packlen + 4;
1516	if (sshbuf_len(state->input) < need)
1517		return 0; /* packet is incomplete */
1518	sshbuf_reset(state->incoming_packet);
1519	if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1520	    state->packlen)) != 0 ||
1521	    (r = sshbuf_consume(state->input, need)) != 0 ||
1522	    (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1523	    (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1524		return r;
1525	if (ssh_packet_log_type(*typep))
1526		debug3_f("type %u", *typep);
1527	/* sshbuf_dump(state->incoming_packet, stderr); */
1528	/* reset for next packet */
1529	state->packlen = 0;
1530	return r;
1531}
1532
1533int
1534ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1535{
1536	struct session_state *state = ssh->state;
1537	u_int padlen, need;
1538	u_char *cp;
1539	u_int maclen, aadlen = 0, authlen = 0, block_size;
1540	struct sshenc *enc   = NULL;
1541	struct sshmac *mac   = NULL;
1542	struct sshcomp *comp = NULL;
1543	int r;
1544
1545	if (state->mux)
1546		return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1547
1548	*typep = SSH_MSG_NONE;
1549
1550	if (state->packet_discard)
1551		return 0;
1552
1553	if (state->newkeys[MODE_IN] != NULL) {
1554		enc  = &state->newkeys[MODE_IN]->enc;
1555		mac  = &state->newkeys[MODE_IN]->mac;
1556		comp = &state->newkeys[MODE_IN]->comp;
1557		/* disable mac for authenticated encryption */
1558		if ((authlen = cipher_authlen(enc->cipher)) != 0)
1559			mac = NULL;
1560	}
1561	maclen = mac && mac->enabled ? mac->mac_len : 0;
1562	block_size = enc ? enc->block_size : 8;
1563	aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1564
1565	if (aadlen && state->packlen == 0) {
1566		if (cipher_get_length(state->receive_context,
1567		    &state->packlen, state->p_read.seqnr,
1568		    sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1569			return 0;
1570		if (state->packlen < 1 + 4 ||
1571		    state->packlen > PACKET_MAX_SIZE) {
1572#ifdef PACKET_DEBUG
1573			sshbuf_dump(state->input, stderr);
1574#endif
1575			logit("Bad packet length %u.", state->packlen);
1576			if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1577				return r;
1578			return SSH_ERR_CONN_CORRUPT;
1579		}
1580		sshbuf_reset(state->incoming_packet);
1581	} else if (state->packlen == 0) {
1582		/*
1583		 * check if input size is less than the cipher block size,
1584		 * decrypt first block and extract length of incoming packet
1585		 */
1586		if (sshbuf_len(state->input) < block_size)
1587			return 0;
1588		sshbuf_reset(state->incoming_packet);
1589		if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1590		    &cp)) != 0)
1591			goto out;
1592		if ((r = cipher_crypt(state->receive_context,
1593		    state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1594		    block_size, 0, 0)) != 0)
1595			goto out;
1596		state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1597		if (state->packlen < 1 + 4 ||
1598		    state->packlen > PACKET_MAX_SIZE) {
1599#ifdef PACKET_DEBUG
1600			fprintf(stderr, "input: \n");
1601			sshbuf_dump(state->input, stderr);
1602			fprintf(stderr, "incoming_packet: \n");
1603			sshbuf_dump(state->incoming_packet, stderr);
1604#endif
1605			logit("Bad packet length %u.", state->packlen);
1606			return ssh_packet_start_discard(ssh, enc, mac, 0,
1607			    PACKET_MAX_SIZE);
1608		}
1609		if ((r = sshbuf_consume(state->input, block_size)) != 0)
1610			goto out;
1611	}
1612	DBG(debug("input: packet len %u", state->packlen+4));
1613
1614	if (aadlen) {
1615		/* only the payload is encrypted */
1616		need = state->packlen;
1617	} else {
1618		/*
1619		 * the payload size and the payload are encrypted, but we
1620		 * have a partial packet of block_size bytes
1621		 */
1622		need = 4 + state->packlen - block_size;
1623	}
1624	DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1625	    " aadlen %d", block_size, need, maclen, authlen, aadlen));
1626	if (need % block_size != 0) {
1627		logit("padding error: need %d block %d mod %d",
1628		    need, block_size, need % block_size);
1629		return ssh_packet_start_discard(ssh, enc, mac, 0,
1630		    PACKET_MAX_SIZE - block_size);
1631	}
1632	/*
1633	 * check if the entire packet has been received and
1634	 * decrypt into incoming_packet:
1635	 * 'aadlen' bytes are unencrypted, but authenticated.
1636	 * 'need' bytes are encrypted, followed by either
1637	 * 'authlen' bytes of authentication tag or
1638	 * 'maclen' bytes of message authentication code.
1639	 */
1640	if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1641		return 0; /* packet is incomplete */
1642#ifdef PACKET_DEBUG
1643	fprintf(stderr, "read_poll enc/full: ");
1644	sshbuf_dump(state->input, stderr);
1645#endif
1646	/* EtM: check mac over encrypted input */
1647	if (mac && mac->enabled && mac->etm) {
1648		if ((r = mac_check(mac, state->p_read.seqnr,
1649		    sshbuf_ptr(state->input), aadlen + need,
1650		    sshbuf_ptr(state->input) + aadlen + need + authlen,
1651		    maclen)) != 0) {
1652			if (r == SSH_ERR_MAC_INVALID)
1653				logit("Corrupted MAC on input.");
1654			goto out;
1655		}
1656	}
1657	if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1658	    &cp)) != 0)
1659		goto out;
1660	if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1661	    sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1662		goto out;
1663	if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1664		goto out;
1665	if (mac && mac->enabled) {
1666		/* Not EtM: check MAC over cleartext */
1667		if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1668		    sshbuf_ptr(state->incoming_packet),
1669		    sshbuf_len(state->incoming_packet),
1670		    sshbuf_ptr(state->input), maclen)) != 0) {
1671			if (r != SSH_ERR_MAC_INVALID)
1672				goto out;
1673			logit("Corrupted MAC on input.");
1674			if (need + block_size > PACKET_MAX_SIZE)
1675				return SSH_ERR_INTERNAL_ERROR;
1676			return ssh_packet_start_discard(ssh, enc, mac,
1677			    sshbuf_len(state->incoming_packet),
1678			    PACKET_MAX_SIZE - need - block_size);
1679		}
1680		/* Remove MAC from input buffer */
1681		DBG(debug("MAC #%d ok", state->p_read.seqnr));
1682		if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1683			goto out;
1684	}
1685
1686	if (seqnr_p != NULL)
1687		*seqnr_p = state->p_read.seqnr;
1688	if (++state->p_read.seqnr == 0) {
1689		if ((ssh->kex->flags & KEX_INITIAL) != 0) {
1690			ssh_packet_disconnect(ssh, "incoming sequence number "
1691			    "wrapped during initial key exchange");
1692		}
1693		logit("incoming seqnr wraps around");
1694	}
1695	if (++state->p_read.packets == 0)
1696		if (!(ssh->compat & SSH_BUG_NOREKEY))
1697			return SSH_ERR_NEED_REKEY;
1698	state->p_read.blocks += (state->packlen + 4) / block_size;
1699	state->p_read.bytes += state->packlen + 4;
1700
1701	/* get padlen */
1702	padlen = sshbuf_ptr(state->incoming_packet)[4];
1703	DBG(debug("input: padlen %d", padlen));
1704	if (padlen < 4)	{
1705		if ((r = sshpkt_disconnect(ssh,
1706		    "Corrupted padlen %d on input.", padlen)) != 0 ||
1707		    (r = ssh_packet_write_wait(ssh)) != 0)
1708			return r;
1709		return SSH_ERR_CONN_CORRUPT;
1710	}
1711
1712	/* skip packet size + padlen, discard padding */
1713	if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1714	    ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1715		goto out;
1716
1717	DBG(debug("input: len before de-compress %zd",
1718	    sshbuf_len(state->incoming_packet)));
1719	if (comp && comp->enabled) {
1720		sshbuf_reset(state->compression_buffer);
1721		if ((r = uncompress_buffer(ssh, state->incoming_packet,
1722		    state->compression_buffer)) != 0)
1723			goto out;
1724		sshbuf_reset(state->incoming_packet);
1725		if ((r = sshbuf_putb(state->incoming_packet,
1726		    state->compression_buffer)) != 0)
1727			goto out;
1728		DBG(debug("input: len after de-compress %zd",
1729		    sshbuf_len(state->incoming_packet)));
1730	}
1731	/*
1732	 * get packet type, implies consume.
1733	 * return length of payload (without type field)
1734	 */
1735	if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1736		goto out;
1737	if (ssh_packet_log_type(*typep))
1738		debug3("receive packet: type %u", *typep);
1739	if (*typep < SSH2_MSG_MIN) {
1740		if ((r = sshpkt_disconnect(ssh,
1741		    "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1742		    (r = ssh_packet_write_wait(ssh)) != 0)
1743			return r;
1744		return SSH_ERR_PROTOCOL_ERROR;
1745	}
1746	if (state->hook_in != NULL &&
1747	    (r = state->hook_in(ssh, state->incoming_packet, typep,
1748	    state->hook_in_ctx)) != 0)
1749		return r;
1750	if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1751		r = ssh_packet_enable_delayed_compress(ssh);
1752	else
1753		r = 0;
1754#ifdef PACKET_DEBUG
1755	fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1756	sshbuf_dump(state->incoming_packet, stderr);
1757#endif
1758	/* reset for next packet */
1759	state->packlen = 0;
1760	if (*typep == SSH2_MSG_NEWKEYS && ssh->kex->kex_strict) {
1761		debug_f("resetting read seqnr %u", state->p_read.seqnr);
1762		state->p_read.seqnr = 0;
1763	}
1764
1765	if ((r = ssh_packet_check_rekey(ssh)) != 0)
1766		return r;
1767 out:
1768	return r;
1769}
1770
1771int
1772ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1773{
1774	struct session_state *state = ssh->state;
1775	u_int reason, seqnr;
1776	int r;
1777	u_char *msg;
1778	const u_char *d;
1779	size_t len;
1780
1781	for (;;) {
1782		msg = NULL;
1783		r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1784		if (r != 0)
1785			return r;
1786		if (*typep == 0) {
1787			/* no message ready */
1788			return 0;
1789		}
1790		state->keep_alive_timeouts = 0;
1791		DBG(debug("received packet type %d", *typep));
1792
1793		/* Always process disconnect messages */
1794		if (*typep == SSH2_MSG_DISCONNECT) {
1795			if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1796			    (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1797				return r;
1798			/* Ignore normal client exit notifications */
1799			do_log2(ssh->state->server_side &&
1800			    reason == SSH2_DISCONNECT_BY_APPLICATION ?
1801			    SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1802			    "Received disconnect from %s port %d:"
1803			    "%u: %.400s", ssh_remote_ipaddr(ssh),
1804			    ssh_remote_port(ssh), reason, msg);
1805			free(msg);
1806			return SSH_ERR_DISCONNECTED;
1807		}
1808
1809		/*
1810		 * Do not implicitly handle any messages here during initial
1811		 * KEX when in strict mode. They will be need to be allowed
1812		 * explicitly by the KEX dispatch table or they will generate
1813		 * protocol errors.
1814		 */
1815		if (ssh->kex != NULL &&
1816		    (ssh->kex->flags & KEX_INITIAL) && ssh->kex->kex_strict)
1817			return 0;
1818		/* Implicitly handle transport-level messages */
1819		switch (*typep) {
1820		case SSH2_MSG_IGNORE:
1821			debug3("Received SSH2_MSG_IGNORE");
1822			break;
1823		case SSH2_MSG_DEBUG:
1824			if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1825			    (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1826			    (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1827				free(msg);
1828				return r;
1829			}
1830			debug("Remote: %.900s", msg);
1831			free(msg);
1832			break;
1833		case SSH2_MSG_UNIMPLEMENTED:
1834			if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1835				return r;
1836			debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1837			    seqnr);
1838			break;
1839		case SSH2_MSG_PING:
1840			if ((r = sshpkt_get_string_direct(ssh, &d, &len)) != 0)
1841				return r;
1842			DBG(debug("Received SSH2_MSG_PING len %zu", len));
1843			if ((r = sshpkt_start(ssh, SSH2_MSG_PONG)) != 0 ||
1844			    (r = sshpkt_put_string(ssh, d, len)) != 0 ||
1845			    (r = sshpkt_send(ssh)) != 0)
1846				return r;
1847			break;
1848		case SSH2_MSG_PONG:
1849			if ((r = sshpkt_get_string_direct(ssh,
1850			    NULL, &len)) != 0)
1851				return r;
1852			DBG(debug("Received SSH2_MSG_PONG len %zu", len));
1853			break;
1854		default:
1855			return 0;
1856		}
1857	}
1858}
1859
1860/*
1861 * Buffers the supplied input data. This is intended to be used together
1862 * with packet_read_poll().
1863 */
1864int
1865ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1866{
1867	struct session_state *state = ssh->state;
1868	int r;
1869
1870	if (state->packet_discard) {
1871		state->keep_alive_timeouts = 0; /* ?? */
1872		if (len >= state->packet_discard) {
1873			if ((r = ssh_packet_stop_discard(ssh)) != 0)
1874				return r;
1875		}
1876		state->packet_discard -= len;
1877		return 0;
1878	}
1879	if ((r = sshbuf_put(state->input, buf, len)) != 0)
1880		return r;
1881
1882	return 0;
1883}
1884
1885/* Reads and buffers data from the specified fd */
1886int
1887ssh_packet_process_read(struct ssh *ssh, int fd)
1888{
1889	struct session_state *state = ssh->state;
1890	int r;
1891	size_t rlen;
1892
1893	if ((r = sshbuf_read(fd, state->input, PACKET_MAX_SIZE, &rlen)) != 0)
1894		return r;
1895
1896	if (state->packet_discard) {
1897		if ((r = sshbuf_consume_end(state->input, rlen)) != 0)
1898			return r;
1899		state->keep_alive_timeouts = 0; /* ?? */
1900		if (rlen >= state->packet_discard) {
1901			if ((r = ssh_packet_stop_discard(ssh)) != 0)
1902				return r;
1903		}
1904		state->packet_discard -= rlen;
1905		return 0;
1906	}
1907	return 0;
1908}
1909
1910int
1911ssh_packet_remaining(struct ssh *ssh)
1912{
1913	return sshbuf_len(ssh->state->incoming_packet);
1914}
1915
1916/*
1917 * Sends a diagnostic message from the server to the client.  This message
1918 * can be sent at any time (but not while constructing another message). The
1919 * message is printed immediately, but only if the client is being executed
1920 * in verbose mode.  These messages are primarily intended to ease debugging
1921 * authentication problems.   The length of the formatted message must not
1922 * exceed 1024 bytes.  This will automatically call ssh_packet_write_wait.
1923 */
1924void
1925ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1926{
1927	char buf[1024];
1928	va_list args;
1929	int r;
1930
1931	if ((ssh->compat & SSH_BUG_DEBUG))
1932		return;
1933
1934	va_start(args, fmt);
1935	vsnprintf(buf, sizeof(buf), fmt, args);
1936	va_end(args);
1937
1938	debug3("sending debug message: %s", buf);
1939
1940	if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1941	    (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1942	    (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1943	    (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1944	    (r = sshpkt_send(ssh)) != 0 ||
1945	    (r = ssh_packet_write_wait(ssh)) != 0)
1946		fatal_fr(r, "send DEBUG");
1947}
1948
1949void
1950sshpkt_fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1951{
1952	snprintf(s, l, "%.200s%s%s port %d",
1953	    ssh->log_preamble ? ssh->log_preamble : "",
1954	    ssh->log_preamble ? " " : "",
1955	    ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1956}
1957
1958/*
1959 * Pretty-print connection-terminating errors and exit.
1960 */
1961static void
1962sshpkt_vfatal(struct ssh *ssh, int r, const char *fmt, va_list ap)
1963{
1964	char *tag = NULL, remote_id[512];
1965	int oerrno = errno;
1966
1967	sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1968
1969	switch (r) {
1970	case SSH_ERR_CONN_CLOSED:
1971		ssh_packet_clear_keys(ssh);
1972		logdie("Connection closed by %s", remote_id);
1973	case SSH_ERR_CONN_TIMEOUT:
1974		ssh_packet_clear_keys(ssh);
1975		logdie("Connection %s %s timed out",
1976		    ssh->state->server_side ? "from" : "to", remote_id);
1977	case SSH_ERR_DISCONNECTED:
1978		ssh_packet_clear_keys(ssh);
1979		logdie("Disconnected from %s", remote_id);
1980	case SSH_ERR_SYSTEM_ERROR:
1981		if (errno == ECONNRESET) {
1982			ssh_packet_clear_keys(ssh);
1983			logdie("Connection reset by %s", remote_id);
1984		}
1985		/* FALLTHROUGH */
1986	case SSH_ERR_NO_CIPHER_ALG_MATCH:
1987	case SSH_ERR_NO_MAC_ALG_MATCH:
1988	case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1989	case SSH_ERR_NO_KEX_ALG_MATCH:
1990	case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1991		if (ssh->kex && ssh->kex->failed_choice) {
1992			ssh_packet_clear_keys(ssh);
1993			errno = oerrno;
1994			logdie("Unable to negotiate with %s: %s. "
1995			    "Their offer: %s", remote_id, ssh_err(r),
1996			    ssh->kex->failed_choice);
1997		}
1998		/* FALLTHROUGH */
1999	default:
2000		if (vasprintf(&tag, fmt, ap) == -1) {
2001			ssh_packet_clear_keys(ssh);
2002			logdie_f("could not allocate failure message");
2003		}
2004		ssh_packet_clear_keys(ssh);
2005		errno = oerrno;
2006		logdie_r(r, "%s%sConnection %s %s",
2007		    tag != NULL ? tag : "", tag != NULL ? ": " : "",
2008		    ssh->state->server_side ? "from" : "to", remote_id);
2009	}
2010}
2011
2012void
2013sshpkt_fatal(struct ssh *ssh, int r, const char *fmt, ...)
2014{
2015	va_list ap;
2016
2017	va_start(ap, fmt);
2018	sshpkt_vfatal(ssh, r, fmt, ap);
2019	/* NOTREACHED */
2020	va_end(ap);
2021	logdie_f("should have exited");
2022}
2023
2024/*
2025 * Logs the error plus constructs and sends a disconnect packet, closes the
2026 * connection, and exits.  This function never returns. The error message
2027 * should not contain a newline.  The length of the formatted message must
2028 * not exceed 1024 bytes.
2029 */
2030void
2031ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
2032{
2033	char buf[1024], remote_id[512];
2034	va_list args;
2035	static int disconnecting = 0;
2036	int r;
2037
2038	if (disconnecting)	/* Guard against recursive invocations. */
2039		fatal("packet_disconnect called recursively.");
2040	disconnecting = 1;
2041
2042	/*
2043	 * Format the message.  Note that the caller must make sure the
2044	 * message is of limited size.
2045	 */
2046	sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
2047	va_start(args, fmt);
2048	vsnprintf(buf, sizeof(buf), fmt, args);
2049	va_end(args);
2050
2051	/* Display the error locally */
2052	logit("Disconnecting %s: %.100s", remote_id, buf);
2053
2054	/*
2055	 * Send the disconnect message to the other side, and wait
2056	 * for it to get sent.
2057	 */
2058	if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
2059		sshpkt_fatal(ssh, r, "%s", __func__);
2060
2061	if ((r = ssh_packet_write_wait(ssh)) != 0)
2062		sshpkt_fatal(ssh, r, "%s", __func__);
2063
2064	/* Close the connection. */
2065	ssh_packet_close(ssh);
2066	cleanup_exit(255);
2067}
2068
2069/*
2070 * Checks if there is any buffered output, and tries to write some of
2071 * the output.
2072 */
2073int
2074ssh_packet_write_poll(struct ssh *ssh)
2075{
2076	struct session_state *state = ssh->state;
2077	int len = sshbuf_len(state->output);
2078	int r;
2079
2080	if (len > 0) {
2081		len = write(state->connection_out,
2082		    sshbuf_ptr(state->output), len);
2083		if (len == -1) {
2084			if (errno == EINTR || errno == EAGAIN)
2085				return 0;
2086			return SSH_ERR_SYSTEM_ERROR;
2087		}
2088		if (len == 0)
2089			return SSH_ERR_CONN_CLOSED;
2090		if ((r = sshbuf_consume(state->output, len)) != 0)
2091			return r;
2092	}
2093	return 0;
2094}
2095
2096/*
2097 * Calls packet_write_poll repeatedly until all pending output data has been
2098 * written.
2099 */
2100int
2101ssh_packet_write_wait(struct ssh *ssh)
2102{
2103	int ret, r, ms_remain = 0;
2104	struct timeval start;
2105	struct timespec timespec, *timespecp = NULL;
2106	struct session_state *state = ssh->state;
2107	struct pollfd pfd;
2108
2109	if ((r = ssh_packet_write_poll(ssh)) != 0)
2110		return r;
2111	while (ssh_packet_have_data_to_write(ssh)) {
2112		pfd.fd = state->connection_out;
2113		pfd.events = POLLOUT;
2114
2115		if (state->packet_timeout_ms > 0) {
2116			ms_remain = state->packet_timeout_ms;
2117			timespecp = &timespec;
2118		}
2119		for (;;) {
2120			if (state->packet_timeout_ms > 0) {
2121				ms_to_timespec(&timespec, ms_remain);
2122				monotime_tv(&start);
2123			}
2124			if ((ret = ppoll(&pfd, 1, timespecp, NULL)) >= 0)
2125				break;
2126			if (errno != EAGAIN && errno != EINTR)
2127				break;
2128			if (state->packet_timeout_ms <= 0)
2129				continue;
2130			ms_subtract_diff(&start, &ms_remain);
2131			if (ms_remain <= 0) {
2132				ret = 0;
2133				break;
2134			}
2135		}
2136		if (ret == 0)
2137			return SSH_ERR_CONN_TIMEOUT;
2138		if ((r = ssh_packet_write_poll(ssh)) != 0)
2139			return r;
2140	}
2141	return 0;
2142}
2143
2144/* Returns true if there is buffered data to write to the connection. */
2145
2146int
2147ssh_packet_have_data_to_write(struct ssh *ssh)
2148{
2149	return sshbuf_len(ssh->state->output) != 0;
2150}
2151
2152/* Returns true if there is not too much data to write to the connection. */
2153
2154int
2155ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
2156{
2157	if (ssh->state->interactive_mode)
2158		return sshbuf_len(ssh->state->output) < 16384;
2159	else
2160		return sshbuf_len(ssh->state->output) < 128 * 1024;
2161}
2162
2163/*
2164 * returns true when there are at most a few keystrokes of data to write
2165 * and the connection is in interactive mode.
2166 */
2167
2168int
2169ssh_packet_interactive_data_to_write(struct ssh *ssh)
2170{
2171	return ssh->state->interactive_mode &&
2172	    sshbuf_len(ssh->state->output) < 256;
2173}
2174
2175void
2176ssh_packet_set_tos(struct ssh *ssh, int tos)
2177{
2178	if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
2179		return;
2180	set_sock_tos(ssh->state->connection_in, tos);
2181}
2182
2183/* Informs that the current session is interactive.  Sets IP flags for that. */
2184
2185void
2186ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
2187{
2188	struct session_state *state = ssh->state;
2189
2190	if (state->set_interactive_called)
2191		return;
2192	state->set_interactive_called = 1;
2193
2194	/* Record that we are in interactive mode. */
2195	state->interactive_mode = interactive;
2196
2197	/* Only set socket options if using a socket.  */
2198	if (!ssh_packet_connection_is_on_socket(ssh))
2199		return;
2200	set_nodelay(state->connection_in);
2201	ssh_packet_set_tos(ssh, interactive ? qos_interactive : qos_bulk);
2202}
2203
2204/* Returns true if the current connection is interactive. */
2205
2206int
2207ssh_packet_is_interactive(struct ssh *ssh)
2208{
2209	return ssh->state->interactive_mode;
2210}
2211
2212int
2213ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
2214{
2215	struct session_state *state = ssh->state;
2216
2217	if (state->set_maxsize_called) {
2218		logit_f("called twice: old %d new %d",
2219		    state->max_packet_size, s);
2220		return -1;
2221	}
2222	if (s < 4 * 1024 || s > 1024 * 1024) {
2223		logit_f("bad size %d", s);
2224		return -1;
2225	}
2226	state->set_maxsize_called = 1;
2227	debug_f("setting to %d", s);
2228	state->max_packet_size = s;
2229	return s;
2230}
2231
2232int
2233ssh_packet_inc_alive_timeouts(struct ssh *ssh)
2234{
2235	return ++ssh->state->keep_alive_timeouts;
2236}
2237
2238void
2239ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
2240{
2241	ssh->state->keep_alive_timeouts = ka;
2242}
2243
2244u_int
2245ssh_packet_get_maxsize(struct ssh *ssh)
2246{
2247	return ssh->state->max_packet_size;
2248}
2249
2250void
2251ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
2252{
2253	debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2254	    (unsigned int)seconds);
2255	ssh->state->rekey_limit = bytes;
2256	ssh->state->rekey_interval = seconds;
2257}
2258
2259time_t
2260ssh_packet_get_rekey_timeout(struct ssh *ssh)
2261{
2262	time_t seconds;
2263
2264	seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
2265	    monotime();
2266	return (seconds <= 0 ? 1 : seconds);
2267}
2268
2269void
2270ssh_packet_set_server(struct ssh *ssh)
2271{
2272	ssh->state->server_side = 1;
2273	ssh->kex->server = 1; /* XXX unify? */
2274}
2275
2276void
2277ssh_packet_set_authenticated(struct ssh *ssh)
2278{
2279	ssh->state->after_authentication = 1;
2280}
2281
2282void *
2283ssh_packet_get_input(struct ssh *ssh)
2284{
2285	return (void *)ssh->state->input;
2286}
2287
2288void *
2289ssh_packet_get_output(struct ssh *ssh)
2290{
2291	return (void *)ssh->state->output;
2292}
2293
2294/* Reset after_authentication and reset compression in post-auth privsep */
2295static int
2296ssh_packet_set_postauth(struct ssh *ssh)
2297{
2298	int r;
2299
2300	debug_f("called");
2301	/* This was set in net child, but is not visible in user child */
2302	ssh->state->after_authentication = 1;
2303	ssh->state->rekeying = 0;
2304	if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2305		return r;
2306	return 0;
2307}
2308
2309/* Packet state (de-)serialization for privsep */
2310
2311/* turn kex into a blob for packet state serialization */
2312static int
2313kex_to_blob(struct sshbuf *m, struct kex *kex)
2314{
2315	int r;
2316
2317	if ((r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2318	    (r = sshbuf_put_cstring(m, kex->hostkey_alg)) != 0 ||
2319	    (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2320	    (r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
2321	    (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2322	    (r = sshbuf_put_u32(m, kex->kex_strict)) != 0 ||
2323	    (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2324	    (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2325	    (r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
2326	    (r = sshbuf_put_stringb(m, kex->server_version)) != 0 ||
2327	    (r = sshbuf_put_stringb(m, kex->session_id)) != 0 ||
2328	    (r = sshbuf_put_u32(m, kex->flags)) != 0)
2329		return r;
2330	return 0;
2331}
2332
2333/* turn key exchange results into a blob for packet state serialization */
2334static int
2335newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2336{
2337	struct sshbuf *b;
2338	struct sshcipher_ctx *cc;
2339	struct sshcomp *comp;
2340	struct sshenc *enc;
2341	struct sshmac *mac;
2342	struct newkeys *newkey;
2343	int r;
2344
2345	if ((newkey = ssh->state->newkeys[mode]) == NULL)
2346		return SSH_ERR_INTERNAL_ERROR;
2347	enc = &newkey->enc;
2348	mac = &newkey->mac;
2349	comp = &newkey->comp;
2350	cc = (mode == MODE_OUT) ? ssh->state->send_context :
2351	    ssh->state->receive_context;
2352	if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2353		return r;
2354	if ((b = sshbuf_new()) == NULL)
2355		return SSH_ERR_ALLOC_FAIL;
2356	if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2357	    (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2358	    (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2359	    (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2360	    (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2361		goto out;
2362	if (cipher_authlen(enc->cipher) == 0) {
2363		if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2364		    (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2365		    (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2366			goto out;
2367	}
2368	if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2369	    (r = sshbuf_put_cstring(b, comp->name)) != 0)
2370		goto out;
2371	r = sshbuf_put_stringb(m, b);
2372 out:
2373	sshbuf_free(b);
2374	return r;
2375}
2376
2377/* serialize packet state into a blob */
2378int
2379ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2380{
2381	struct session_state *state = ssh->state;
2382	int r;
2383
2384	if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2385	    (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2386	    (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2387	    (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2388	    (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2389	    (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2390	    (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2391	    (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2392	    (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2393	    (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2394	    (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2395	    (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2396	    (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2397	    (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2398	    (r = sshbuf_put_stringb(m, state->output)) != 0)
2399		return r;
2400
2401	return 0;
2402}
2403
2404/* restore key exchange results from blob for packet state de-serialization */
2405static int
2406newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2407{
2408	struct sshbuf *b = NULL;
2409	struct sshcomp *comp;
2410	struct sshenc *enc;
2411	struct sshmac *mac;
2412	struct newkeys *newkey = NULL;
2413	size_t keylen, ivlen, maclen;
2414	int r;
2415
2416	if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2417		r = SSH_ERR_ALLOC_FAIL;
2418		goto out;
2419	}
2420	if ((r = sshbuf_froms(m, &b)) != 0)
2421		goto out;
2422#ifdef DEBUG_PK
2423	sshbuf_dump(b, stderr);
2424#endif
2425	enc = &newkey->enc;
2426	mac = &newkey->mac;
2427	comp = &newkey->comp;
2428
2429	if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2430	    (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2431	    (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2432	    (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2433	    (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2434		goto out;
2435	if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2436		r = SSH_ERR_INVALID_FORMAT;
2437		goto out;
2438	}
2439	if (cipher_authlen(enc->cipher) == 0) {
2440		if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2441			goto out;
2442		if ((r = mac_setup(mac, mac->name)) != 0)
2443			goto out;
2444		if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2445		    (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2446			goto out;
2447		if (maclen > mac->key_len) {
2448			r = SSH_ERR_INVALID_FORMAT;
2449			goto out;
2450		}
2451		mac->key_len = maclen;
2452	}
2453	if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2454	    (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2455		goto out;
2456	if (sshbuf_len(b) != 0) {
2457		r = SSH_ERR_INVALID_FORMAT;
2458		goto out;
2459	}
2460	enc->key_len = keylen;
2461	enc->iv_len = ivlen;
2462	ssh->kex->newkeys[mode] = newkey;
2463	newkey = NULL;
2464	r = 0;
2465 out:
2466	free(newkey);
2467	sshbuf_free(b);
2468	return r;
2469}
2470
2471/* restore kex from blob for packet state de-serialization */
2472static int
2473kex_from_blob(struct sshbuf *m, struct kex **kexp)
2474{
2475	struct kex *kex;
2476	int r;
2477
2478	if ((kex = kex_new()) == NULL)
2479		return SSH_ERR_ALLOC_FAIL;
2480	if ((r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2481	    (r = sshbuf_get_cstring(m, &kex->hostkey_alg, NULL)) != 0 ||
2482	    (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2483	    (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
2484	    (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2485	    (r = sshbuf_get_u32(m, &kex->kex_strict)) != 0 ||
2486	    (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2487	    (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2488	    (r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
2489	    (r = sshbuf_get_stringb(m, kex->server_version)) != 0 ||
2490	    (r = sshbuf_get_stringb(m, kex->session_id)) != 0 ||
2491	    (r = sshbuf_get_u32(m, &kex->flags)) != 0)
2492		goto out;
2493	kex->server = 1;
2494	kex->done = 1;
2495	r = 0;
2496 out:
2497	if (r != 0 || kexp == NULL) {
2498		kex_free(kex);
2499		if (kexp != NULL)
2500			*kexp = NULL;
2501	} else {
2502		kex_free(*kexp);
2503		*kexp = kex;
2504	}
2505	return r;
2506}
2507
2508/*
2509 * Restore packet state from content of blob 'm' (de-serialization).
2510 * Note that 'm' will be partially consumed on parsing or any other errors.
2511 */
2512int
2513ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2514{
2515	struct session_state *state = ssh->state;
2516	const u_char *input, *output;
2517	size_t ilen, olen;
2518	int r;
2519
2520	if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2521	    (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2522	    (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2523	    (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2524	    (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2525	    (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2526	    (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2527	    (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2528	    (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2529	    (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2530	    (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2531	    (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2532	    (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2533		return r;
2534	/*
2535	 * We set the time here so that in post-auth privsep child we
2536	 * count from the completion of the authentication.
2537	 */
2538	state->rekey_time = monotime();
2539	/* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2540	if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2541	    (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2542		return r;
2543
2544	if ((r = ssh_packet_set_postauth(ssh)) != 0)
2545		return r;
2546
2547	sshbuf_reset(state->input);
2548	sshbuf_reset(state->output);
2549	if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2550	    (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2551	    (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2552	    (r = sshbuf_put(state->output, output, olen)) != 0)
2553		return r;
2554
2555	if (sshbuf_len(m))
2556		return SSH_ERR_INVALID_FORMAT;
2557	debug3_f("done");
2558	return 0;
2559}
2560
2561/* NEW API */
2562
2563/* put data to the outgoing packet */
2564
2565int
2566sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2567{
2568	return sshbuf_put(ssh->state->outgoing_packet, v, len);
2569}
2570
2571int
2572sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2573{
2574	return sshbuf_putb(ssh->state->outgoing_packet, b);
2575}
2576
2577int
2578sshpkt_put_u8(struct ssh *ssh, u_char val)
2579{
2580	return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2581}
2582
2583int
2584sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2585{
2586	return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2587}
2588
2589int
2590sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2591{
2592	return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2593}
2594
2595int
2596sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2597{
2598	return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2599}
2600
2601int
2602sshpkt_put_cstring(struct ssh *ssh, const void *v)
2603{
2604	return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2605}
2606
2607int
2608sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2609{
2610	return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2611}
2612
2613#ifdef WITH_OPENSSL
2614int
2615sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2616{
2617	return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2618}
2619
2620
2621int
2622sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2623{
2624	return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2625}
2626#endif /* WITH_OPENSSL */
2627
2628/* fetch data from the incoming packet */
2629
2630int
2631sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2632{
2633	return sshbuf_get(ssh->state->incoming_packet, valp, len);
2634}
2635
2636int
2637sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2638{
2639	return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2640}
2641
2642int
2643sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2644{
2645	return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2646}
2647
2648int
2649sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2650{
2651	return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2652}
2653
2654int
2655sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2656{
2657	return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2658}
2659
2660int
2661sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2662{
2663	return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2664}
2665
2666int
2667sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2668{
2669	return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2670}
2671
2672int
2673sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2674{
2675	return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2676}
2677
2678int
2679sshpkt_getb_froms(struct ssh *ssh, struct sshbuf **valp)
2680{
2681	return sshbuf_froms(ssh->state->incoming_packet, valp);
2682}
2683
2684#ifdef WITH_OPENSSL
2685int
2686sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2687{
2688	return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2689}
2690
2691int
2692sshpkt_get_bignum2(struct ssh *ssh, BIGNUM **valp)
2693{
2694	return sshbuf_get_bignum2(ssh->state->incoming_packet, valp);
2695}
2696#endif /* WITH_OPENSSL */
2697
2698int
2699sshpkt_get_end(struct ssh *ssh)
2700{
2701	if (sshbuf_len(ssh->state->incoming_packet) > 0)
2702		return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2703	return 0;
2704}
2705
2706const u_char *
2707sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2708{
2709	if (lenp != NULL)
2710		*lenp = sshbuf_len(ssh->state->incoming_packet);
2711	return sshbuf_ptr(ssh->state->incoming_packet);
2712}
2713
2714/* start a new packet */
2715
2716int
2717sshpkt_start(struct ssh *ssh, u_char type)
2718{
2719	u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
2720
2721	DBG(debug("packet_start[%d]", type));
2722	memset(buf, 0, sizeof(buf));
2723	buf[sizeof(buf) - 1] = type;
2724	sshbuf_reset(ssh->state->outgoing_packet);
2725	return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
2726}
2727
2728static int
2729ssh_packet_send_mux(struct ssh *ssh)
2730{
2731	struct session_state *state = ssh->state;
2732	u_char type, *cp;
2733	size_t len;
2734	int r;
2735
2736	if (ssh->kex)
2737		return SSH_ERR_INTERNAL_ERROR;
2738	len = sshbuf_len(state->outgoing_packet);
2739	if (len < 6)
2740		return SSH_ERR_INTERNAL_ERROR;
2741	cp = sshbuf_mutable_ptr(state->outgoing_packet);
2742	type = cp[5];
2743	if (ssh_packet_log_type(type))
2744		debug3_f("type %u", type);
2745	/* drop everything, but the connection protocol */
2746	if (type >= SSH2_MSG_CONNECTION_MIN &&
2747	    type <= SSH2_MSG_CONNECTION_MAX) {
2748		POKE_U32(cp, len - 4);
2749		if ((r = sshbuf_putb(state->output,
2750		    state->outgoing_packet)) != 0)
2751			return r;
2752		/* sshbuf_dump(state->output, stderr); */
2753	}
2754	sshbuf_reset(state->outgoing_packet);
2755	return 0;
2756}
2757
2758/*
2759 * 9.2.  Ignored Data Message
2760 *
2761 *   byte      SSH_MSG_IGNORE
2762 *   string    data
2763 *
2764 * All implementations MUST understand (and ignore) this message at any
2765 * time (after receiving the protocol version). No implementation is
2766 * required to send them. This message can be used as an additional
2767 * protection measure against advanced traffic analysis techniques.
2768 */
2769int
2770sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2771{
2772	u_int32_t rnd = 0;
2773	int r;
2774	u_int i;
2775
2776	if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2777	    (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2778		return r;
2779	for (i = 0; i < nbytes; i++) {
2780		if (i % 4 == 0)
2781			rnd = arc4random();
2782		if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2783			return r;
2784		rnd >>= 8;
2785	}
2786	return 0;
2787}
2788
2789/* send it */
2790
2791int
2792sshpkt_send(struct ssh *ssh)
2793{
2794	if (ssh->state && ssh->state->mux)
2795		return ssh_packet_send_mux(ssh);
2796	return ssh_packet_send2(ssh);
2797}
2798
2799int
2800sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2801{
2802	char buf[1024];
2803	va_list args;
2804	int r;
2805
2806	va_start(args, fmt);
2807	vsnprintf(buf, sizeof(buf), fmt, args);
2808	va_end(args);
2809
2810	debug2_f("sending SSH2_MSG_DISCONNECT: %s", buf);
2811	if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2812	    (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2813	    (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2814	    (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2815	    (r = sshpkt_send(ssh)) != 0)
2816		return r;
2817	return 0;
2818}
2819
2820/* roundup current message to pad bytes */
2821int
2822sshpkt_add_padding(struct ssh *ssh, u_char pad)
2823{
2824	ssh->state->extra_pad = pad;
2825	return 0;
2826}
2827