1 /* site.c - manage communication with a remote network site */
4 * This file is part of secnet.
5 * See README for full list of copyright holders.
7 * secnet is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3 of the License, or
10 * (at your option) any later version.
12 * secnet is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * version 3 along with secnet; if not, see
19 * https://www.gnu.org/licenses/gpl.html.
22 /* The 'site' code doesn't know anything about the structure of the
23 packets it's transmitting. In fact, under the new netlink
24 configuration scheme it doesn't need to know anything at all about
25 IP addresses, except how to contact its peer. This means it could
26 potentially be used to tunnel other protocols too (IPv6, IPX, plain
27 old Ethernet frames) if appropriate netlink code can be written
28 (and that ought not to be too hard, eg. using the TUN/TAP device to
29 pretend to be an Ethernet interface). */
31 /* At some point in the future the netlink code will be asked for
32 configuration information to go in the PING/PONG packets at the end
33 of the key exchange. */
40 #include <sys/socket.h>
44 #include "unaligned.h"
48 #define SETUP_BUFFER_LEN 2048
50 #define DEFAULT_KEY_LIFETIME (3600*1000) /* [ms] */
51 #define DEFAULT_KEY_RENEGOTIATE_GAP (5*60*1000) /* [ms] */
52 #define DEFAULT_SETUP_RETRIES 5
53 #define DEFAULT_SETUP_RETRY_INTERVAL (2*1000) /* [ms] */
54 #define DEFAULT_WAIT_TIME (20*1000) /* [ms] */
56 #define DEFAULT_MOBILE_KEY_LIFETIME (2*24*3600*1000) /* [ms] */
57 #define DEFAULT_MOBILE_KEY_RENEGOTIATE_GAP (12*3600*1000) /* [ms] */
58 #define DEFAULT_MOBILE_SETUP_RETRIES 30
59 #define DEFAULT_MOBILE_SETUP_RETRY_INTERVAL (1*1000) /* [ms] */
60 #define DEFAULT_MOBILE_WAIT_TIME (10*1000) /* [ms] */
62 #define DEFAULT_MOBILE_PEER_EXPIRY (2*60) /* [s] */
64 #define PEERKEYS_SUFFIX_MAXLEN (sizeof("~incoming")-1)
66 /* Each site can be in one of several possible states. */
69 SITE_STOP - nothing is allowed to happen; tunnel is down;
70 all session keys have been erased
71 -> SITE_RUN upon external instruction
72 SITE_RUN - site up, maybe with valid key
73 -> SITE_RESOLVE upon outgoing packet and no valid key
74 we start name resolution for the other end of the tunnel
75 -> SITE_SENTMSG2 upon valid incoming message 1 and suitable time
76 we send an appropriate message 2
77 SITE_RESOLVE - waiting for name resolution
78 -> SITE_SENTMSG1 upon successful resolution
79 we send an appropriate message 1
80 -> SITE_SENTMSG2 upon valid incoming message 1 (then abort resolution)
81 we abort resolution and
82 -> SITE_WAIT on timeout or resolution failure
84 -> SITE_SENTMSG2 upon valid incoming message 1 from higher priority end
85 -> SITE_SENTMSG3 upon valid incoming message 2
86 -> SITE_WAIT on timeout
88 -> SITE_SENTMSG4 upon valid incoming message 3
89 -> SITE_WAIT on timeout
91 -> SITE_SENTMSG5 upon valid incoming message 4
92 -> SITE_WAIT on timeout
94 -> SITE_RUN upon valid incoming message 5
95 -> SITE_WAIT on timeout
97 -> SITE_RUN upon valid incoming message 6
98 -> SITE_WAIT on timeout
99 SITE_WAIT - failed to establish key; do nothing for a while
100 -> SITE_RUN on timeout
105 #define SITE_RESOLVE 2
106 #define SITE_SENTMSG1 3
107 #define SITE_SENTMSG2 4
108 #define SITE_SENTMSG3 5
109 #define SITE_SENTMSG4 6
110 #define SITE_SENTMSG5 7
113 #define CASES_MSG3_KNOWN LABEL_MSG3: case LABEL_MSG3BIS
117 int32_t site_max_start_pad = 4*4;
119 static cstring_t state_name(uint32_t state)
122 case 0: return "STOP";
123 case 1: return "RUN";
124 case 2: return "RESOLVE";
125 case 3: return "SENTMSG1";
126 case 4: return "SENTMSG2";
127 case 5: return "SENTMSG3";
128 case 6: return "SENTMSG4";
129 case 7: return "SENTMSG5";
130 case 8: return "WAIT";
131 default: return "*bad state*";
137 #define LOG_UNEXPECTED 0x00000001
138 #define LOG_SETUP_INIT 0x00000002
139 #define LOG_SETUP_TIMEOUT 0x00000004
140 #define LOG_ACTIVATE_KEY 0x00000008
141 #define LOG_TIMEOUT_KEY 0x00000010
142 #define LOG_SEC 0x00000020
143 #define LOG_STATE 0x00000040
144 #define LOG_DROP 0x00000080
145 #define LOG_DUMP 0x00000100
146 #define LOG_ERROR 0x00000400
147 #define LOG_PEER_ADDRS 0x00000800
148 #define LOG_SIGKEYS 0x00001000
150 static struct flagstr log_event_table[]={
151 { "unexpected", LOG_UNEXPECTED },
152 { "setup-init", LOG_SETUP_INIT },
153 { "setup-timeout", LOG_SETUP_TIMEOUT },
154 { "activate-key", LOG_ACTIVATE_KEY },
155 { "timeout-key", LOG_TIMEOUT_KEY },
156 { "security", LOG_SEC },
157 { "state-change", LOG_STATE },
158 { "packet-drop", LOG_DROP },
159 { "dump-packets", LOG_DUMP },
160 { "errors", LOG_ERROR },
161 { "peer-addrs", LOG_PEER_ADDRS },
162 { "sigkeys", LOG_SIGKEYS },
163 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
164 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR|LOG_SIGKEYS },
165 { "all", 0xffffffff },
170 /***** TRANSPORT PEERS declarations *****/
172 /* Details of "mobile peer" semantics:
174 - We use the same data structure for the different configurations,
175 but manage it with different algorithms.
177 - We record up to mobile_peers_max peer address/port numbers
178 ("peers") for key setup, and separately up to mobile_peers_max
181 - In general, we make a new set of addrs (see below) when we start
182 a new key exchange; the key setup addrs become the data transport
183 addrs when key setup complets.
185 If our peer is mobile:
187 - We send to all recent addresses of incoming packets, plus
188 initially all configured addresses (which we also expire).
190 - So, we record addrs of good incoming packets, as follows:
191 1. expire any peers last seen >120s ("mobile-peer-expiry") ago
192 2. add the peer of the just received packet to the applicable list
193 (possibly evicting the oldest entries to make room)
194 NB that we do not expire peers until an incoming packet arrives.
196 - If the peer has a configured address or name, we record them the
197 same way, but only as a result of our own initiation of key
198 setup. (We might evict some incoming packet addrs to make room.)
200 - The default number of addrs to keep is 3, or 4 if we have a
201 configured name or address. That's space for two configured
202 addresses (one IPv6 and one IPv4), plus two received addresses.
204 - Outgoing packets are sent to every recorded address in the
205 applicable list. Any unsupported[1] addresses are deleted from
206 the list right away. (This should only happen to configured
207 addresses, of course, but there is no need to check that.)
209 - When we successfully complete a key setup, we merge the key setup
210 peers into the data transfer peers.
212 [1] An unsupported address is one for whose AF we don't have a
213 socket (perhaps because we got EAFNOSUPPORT or some such) or for
214 which sendto gives ENETUNREACH.
216 If neither end is mobile:
218 - When peer initiated the key exchange, we use the incoming packet
221 - When we initiate the key exchange, we try configured addresses
222 until we get one which isn't unsupported then fixate on that.
224 - When we complete a key setup, we replace the data transport peers
225 with those from the key setup.
229 - We can't tell when local network setup changes so we can't cache
230 the unsupported addrs and completely remove the spurious calls to
231 sendto, but we can optimise things a bit by deprioritising addrs
232 which seem to be unsupported.
234 - Use only configured addresses. (Except, that if our peer
235 initiated a key exchange we use the incoming packet address until
236 our name resolution completes.)
238 - When we send a packet, try each address in turn; if addr
239 supported, put that address to the end of the list for future
240 packets, and go onto the next address.
242 - When we complete a key setup, we replace the data transport peers
243 with those from the key setup.
249 struct comm_addr addr;
253 /* configuration information */
254 /* runtime information */
256 transport_peer peers[MAX_PEER_ADDRS];
259 /* Basic operations on transport peer address sets */
260 static void transport_peers_clear(struct site *st, transport_peers *peers);
261 static int transport_peers_valid(transport_peers *peers);
262 static void transport_peers_copy(struct site *st, transport_peers *dst,
263 const transport_peers *src);
265 /* Record address of incoming setup packet; resp. data packet. */
266 static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
267 static void transport_data_msgok(struct site *st, const struct comm_addr *a);
269 /* Initialise the setup addresses. Called before we send the first
270 * packet in a key exchange. If we are the initiator, as a result of
271 * resolve completing (or being determined not to be relevant) or an
272 * incoming PROD; if we are the responder, as a result of the MSG1. */
273 static bool_t transport_compute_setupinit_peers(struct site *st,
274 const struct comm_addr *configured_addrs /* 0 if none or not found */,
275 int n_configured_addrs /* 0 if none or not found */,
276 const struct comm_addr *incoming_packet_addr /* 0 if none */);
278 /* Called if we are the responder in a key setup, when the resolve
279 * completes. transport_compute_setupinit_peers will hvae been called
280 * earlier. If _complete is called, we are still doing the key setup
281 * (and we should use the new values for both the rest of the key
282 * setup and the ongoing data exchange); if _tardy is called, the key
283 * setup is done (either completed or not) and only the data peers are
285 static void transport_resolve_complete(struct site *st,
286 const struct comm_addr *addrs, int naddrs);
287 static void transport_resolve_complete_tardy(struct site *st,
288 const struct comm_addr *addrs, int naddrs);
290 static void transport_xmit(struct site *st, transport_peers *peers,
291 struct buffer_if *buf, bool_t candebug);
293 /***** END of transport peers declarations *****/
297 struct transform_inst_if *transform;
298 uint64_t key_timeout; /* End of life of current key */
299 uint32_t remote_session_id;
305 /* configuration information */
309 bool_t local_mobile, peer_mobile; /* Mobile client support */
310 int32_t transport_peers_max;
311 string_t tunname; /* localname<->remotename by default, used in logs */
312 cstring_t *addresses; /* DNS name or address(es) for bootstrapping, optional */
313 int remoteport; /* Port for bootstrapping, optional */
315 struct netlink_if *netlink;
316 struct comm_if **comms;
317 struct comm_clientinfo **commclientinfos;
319 struct resolver_if *resolver;
321 struct hash_if *defhash;
322 struct random_if *random;
323 struct privcache_if *privkeys;
324 struct sigprivkey_if *privkey_fixed;
325 struct transform_if **transforms;
329 uint32_t index; /* Index of this site */
330 uint32_t early_capabilities;
331 uint32_t local_capabilities;
332 int32_t setup_retries; /* How many times to send setup packets */
333 int32_t setup_retry_interval; /* Initial timeout for setup packets */
334 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
335 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
336 int32_t key_lifetime; /* How long a key lasts once set up */
337 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
338 after this time, initiate a new
341 bool_t our_name_later; /* our name > peer name */
344 /* runtime information */
346 uint64_t now; /* Most recently seen time */
347 bool_t allow_send_prod;
348 bool_t msg1_crossed_logged;
350 int resolving_n_results_all;
351 int resolving_n_results_stored;
352 struct comm_addr resolving_results[MAX_PEER_ADDRS];
353 const char *peerkeys_path;
354 struct pathprefix_template peerkeys_tmpl;
355 struct peer_keyset *peerkeys_current, *peerkeys_kex;
357 /* The currently established session */
358 struct data_key current;
359 struct data_key auxiliary_key;
360 bool_t auxiliary_is_new;
361 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
362 uint64_t auxiliary_renegotiate_key_time;
363 transport_peers peers; /* Current address(es) of peer for data traffic */
365 /* The current key setup protocol exchange. We can only be
366 involved in one of these at a time. There's a potential for
367 denial of service here (the attacker keeps sending a setup
368 packet; we keep trying to continue the exchange, and have to
369 timeout before we can listen for another setup packet); perhaps
370 we should keep a list of 'bad' sources for setup packets. */
371 uint32_t remote_capabilities;
372 uint16_t remote_adv_mtu;
373 struct transform_if *chosen_transform;
374 uint32_t setup_session_id;
375 transport_peers setup_peers;
376 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
377 uint8_t remoteN[NONCELEN];
378 struct buffer_if buffer; /* Current outgoing key exchange packet */
379 struct buffer_if scratch;
380 int32_t retries; /* Number of retries remaining */
381 uint64_t timeout; /* Timeout for current state */
383 uint8_t *sharedsecret;
384 uint32_t sharedsecretlen, sharedsecretallocd;
385 struct transform_inst_if *new_transform; /* For key setup/verify */
388 static uint32_t event_log_priority(struct site *st, uint32_t event)
390 if (!(event&st->log_events))
393 case LOG_UNEXPECTED: return M_INFO;
394 case LOG_SETUP_INIT: return M_INFO;
395 case LOG_SETUP_TIMEOUT: return M_NOTICE;
396 case LOG_ACTIVATE_KEY: return M_INFO;
397 case LOG_TIMEOUT_KEY: return M_INFO;
398 case LOG_SEC: return M_SECURITY;
399 case LOG_STATE: return M_DEBUG;
400 case LOG_DROP: return M_DEBUG;
401 case LOG_DUMP: return M_DEBUG;
402 case LOG_ERROR: return M_ERR;
403 case LOG_PEER_ADDRS: return M_DEBUG;
404 case LOG_SIGKEYS: return M_INFO;
405 default: return M_ERR;
409 static uint32_t slog_start(struct site *st, uint32_t event)
411 uint32_t class=event_log_priority(st, event);
413 slilog_part(st->log,class,"%s: ",st->tunname);
418 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
420 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
424 class=slog_start(st,event);
426 vslilog_part(st->log,class,msg,ap);
427 slilog_part(st->log,class,"\n");
431 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
433 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
437 vslog(st,event,msg,ap);
441 static void logtimeout(struct site *st, const char *fmt, ...)
443 static void logtimeout(struct site *st, const char *fmt, ...)
445 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
452 slilog_part(st->log,class,"%s: ",st->tunname);
453 vslilog_part(st->log,class,fmt,ap);
457 for (i=0, delim=" (tried ";
458 i<st->setup_peers.npeers;
460 transport_peer *peer=&st->setup_peers.peers[i];
461 const char *s=comm_addr_to_string(&peer->addr);
462 slilog_part(st->log,class,"%s%s",delim,s);
465 slilog_part(st->log,class,")\n");
469 static void set_link_quality(struct site *st);
470 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
471 static void delete_one_key(struct site *st, struct data_key *key,
472 const char *reason /* may be 0 meaning don't log*/,
473 const char *which /* ignored if !reasonn */,
474 uint32_t loglevel /* ignored if !reasonn */);
475 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
476 const struct comm_addr *prod_hint);
477 static void enter_state_run(struct site *st);
478 static bool_t enter_state_resolve(struct site *st);
479 static void decrement_resolving_count(struct site *st, int by);
480 static bool_t enter_new_state(struct site *st,uint32_t next,
481 const struct msg *prompt
482 /* may be 0 for SENTMSG1 */);
483 static void enter_state_wait(struct site *st);
484 static void activate_new_key(struct site *st);
486 static bool_t is_transform_valid(struct transform_inst_if *transform)
488 return transform && transform->valid(transform->st);
491 static bool_t current_valid(struct site *st)
493 return is_transform_valid(st->current.transform);
496 #define DEFINE_CALL_TRANSFORM(fwdrev) \
497 static transform_apply_return \
498 call_transform_##fwdrev(struct site *st, \
499 struct transform_inst_if *transform, \
500 struct buffer_if *buf, \
501 const char **errmsg) \
503 if (!is_transform_valid(transform)) { \
504 *errmsg="transform not set up"; \
505 return transform_apply_err; \
507 return transform->fwdrev(transform->st,buf,errmsg); \
510 DEFINE_CALL_TRANSFORM(forwards)
511 DEFINE_CALL_TRANSFORM(reverse)
513 static void dispose_transform(struct transform_inst_if **transform_var)
515 struct transform_inst_if *transform=*transform_var;
517 transform->delkey(transform->st);
518 transform->destroy(transform->st);
523 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
524 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
525 #define CHECK_TYPE(b,t) do { uint32_t type; \
526 CHECK_AVAIL((b),4); \
527 type=buf_unprepend_uint32((b)); \
528 if (type!=(t)) return False; } while(0)
530 static _Bool type_is_msg23(uint32_t type)
533 case LABEL_MSG2: case CASES_MSG3_KNOWN: return True;
534 default: return False;
537 static _Bool type_is_msg34(uint32_t type)
540 case CASES_MSG3_KNOWN: case LABEL_MSG4: return True;
541 default: return False;
548 struct buffer_if extrainfo;
555 struct parsedname remote;
556 struct parsedname local;
557 uint32_t remote_capabilities;
559 int capab_transformnum;
565 struct alg_msg_data sig;
566 int n_pubkeys_accepted_nom; /* may be > MAX_SIG_KEYS ! */
567 const struct sigkeyid *pubkeys_accepted[MAX_SIG_KEYS];
568 int signing_key_index;
571 static const struct sigkeyid keyid_zero;
573 static int32_t wait_timeout(struct site *st) {
574 int32_t t = st->wait_timeout_mean;
577 st->random->generate(st->random->st,sizeof(factor),&factor);
578 t += (t / 256) * factor;
583 static _Bool set_new_transform(struct site *st, char *pk)
587 /* Make room for the shared key */
588 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
589 assert(st->sharedsecretlen);
590 if (st->sharedsecretlen > st->sharedsecretallocd) {
591 st->sharedsecretallocd=st->sharedsecretlen;
592 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
593 st->sharedsecretallocd,
594 "site:sharedsecret");
597 /* Generate the shared key */
598 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
599 st->sharedsecret,st->sharedsecretlen);
601 /* Set up the transform */
602 struct transform_if *generator=st->chosen_transform;
603 struct transform_inst_if *generated=generator->create(generator->st);
604 ok = generated->setkey(generated->st,st->sharedsecret,
605 st->sharedsecretlen,st->our_name_later);
607 dispose_transform(&st->new_transform);
608 if (!ok) return False;
609 st->new_transform=generated;
611 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
612 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
613 st->chosen_transform->capab_bit,
614 st->local_capabilities, st->remote_capabilities);
619 int32_t lenpos, afternul;
621 static void append_string_xinfo_start(struct buffer_if *buf,
622 struct xinfoadd *xia,
624 /* Helps construct one of the names with additional info as found
625 * in MSG1..4. Call this function first, then append all the
626 * desired extra info (not including the nul byte) to the buffer,
627 * then call append_string_xinfo_done. */
629 xia->lenpos = buf->size;
630 buf_append_string(buf,str);
631 buf_append_uint8(buf,0);
632 xia->afternul = buf->size;
634 static void append_string_xinfo_done(struct buffer_if *buf,
635 struct xinfoadd *xia)
637 /* we just need to adjust the string length */
638 if (buf->size == xia->afternul) {
639 /* no extra info, strip the nul too */
640 buf_unappend_uint8(buf);
642 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
646 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
647 out using a transform of config data supplied by netlink */
648 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what,
649 const struct msg *prompt
650 /* may be 0 for MSG1 */)
656 st->retries=st->setup_retries;
657 BUF_ALLOC(&st->buffer,what);
658 buffer_init(&st->buffer,0);
659 buf_append_uint32(&st->buffer,
660 (type==LABEL_MSG1?0:st->setup_session_id));
661 buf_append_uint32(&st->buffer,st->index);
662 buf_append_uint32(&st->buffer,type);
665 append_string_xinfo_start(&st->buffer,&xia,st->localname);
666 if ((st->local_capabilities & st->early_capabilities) ||
667 (type != LABEL_MSG1)) {
668 buf_append_uint32(&st->buffer,st->local_capabilities);
670 if (type_is_msg34(type)) {
671 buf_append_uint16(&st->buffer,st->mtu_target);
673 if (type_is_msg23(type)) {
674 buf_append_uint8(&st->buffer,st->peerkeys_kex->nkeys);
675 for (ki=0; ki<st->peerkeys_kex->nkeys; ki++) {
676 struct peer_pubkey *pk = &st->peerkeys_kex->keys[ki];
677 BUF_ADD_OBJ(append,&st->buffer,pk->id);
680 struct sigprivkey_if *privkey=0;
681 if (type_is_msg34(type)) {
682 assert(prompt->n_pubkeys_accepted_nom>0);
684 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
686 const struct sigkeyid *kid=prompt->pubkeys_accepted[ki];
688 privkey=st->privkeys->lookup(st->privkeys->st,kid,st->log);
689 if (privkey) goto privkey_found;
691 if (sigkeyid_equal(&keyid_zero,kid)) {
692 privkey=st->privkey_fixed;
697 uint32_t class = slog_start(st,LOG_ERROR);
699 slilog_part(st->log,class,"no suitable private key, peer wanted");
701 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
703 slilog_part(st->log,class, " " SIGKEYID_PR_FMT,
704 SIGKEYID_PR_VAL(prompt->pubkeys_accepted[ki]));
706 if (prompt->n_pubkeys_accepted_nom > MAX_SIG_KEYS)
707 slilog_part(st->log,class," +%d",
708 prompt->n_pubkeys_accepted_nom - MAX_SIG_KEYS);
709 slilog_part(st->log,class,"\n");
714 buf_append_uint8(&st->buffer,ki);
717 append_string_xinfo_done(&st->buffer,&xia);
719 buf_append_string(&st->buffer,st->remotename);
720 BUF_ADD_OBJ(append,&st->buffer,st->localN);
721 if (type==LABEL_MSG1) return True;
722 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
723 if (type==LABEL_MSG2) return True;
725 if (hacky_par_mid_failnow()) return False;
727 if (MSGMAJOR(type) == 3) do {
728 minor = MSGMINOR(type);
729 if (minor < 1) break;
730 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
733 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
734 buf_append_string(&st->buffer,dhpub);
737 bool_t ok=privkey->sign(privkey->st,
748 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
751 nm->len=buf_unprepend_uint16(msg);
752 CHECK_AVAIL(msg,nm->len);
753 nm->name=buf_unprepend(msg,nm->len);
754 uint8_t *nul=memchr(nm->name,0,nm->len);
756 buffer_readonly_view(&nm->extrainfo,0,0);
758 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
759 nm->len=nul-nm->name;
764 static bool_t unpick_msg(struct site *st, uint32_t type,
765 struct buffer_if *msg, struct msg *m)
769 m->n_pubkeys_accepted_nom=-1;
770 m->capab_transformnum=-1;
771 m->signing_key_index=-1;
772 m->hashstart=msg->start;
774 m->dest=buf_unprepend_uint32(msg);
776 m->source=buf_unprepend_uint32(msg);
777 CHECK_TYPE(msg,type);
778 if (!unpick_name(msg,&m->remote)) return False;
779 m->remote_capabilities=0;
781 if (m->remote.extrainfo.size) {
782 CHECK_AVAIL(&m->remote.extrainfo,4);
783 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
785 if (type_is_msg34(type) && m->remote.extrainfo.size) {
786 CHECK_AVAIL(&m->remote.extrainfo,2);
787 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
789 if (type_is_msg23(type) && m->remote.extrainfo.size) {
790 m->n_pubkeys_accepted_nom = buf_unprepend_uint8(&m->remote.extrainfo);
791 if (!m->n_pubkeys_accepted_nom) return False;
792 for (int ki_nom=0; ki_nom<m->n_pubkeys_accepted_nom; ki_nom++) {
793 CHECK_AVAIL(&m->remote.extrainfo,KEYIDSZ);
794 struct sigkeyid *kid = buf_unprepend(&m->remote.extrainfo,KEYIDSZ);
795 if (ki_nom<MAX_SIG_KEYS) m->pubkeys_accepted[ki_nom] = kid;
798 m->n_pubkeys_accepted_nom = 1;
799 m->pubkeys_accepted[0] = &keyid_zero;
801 if (type_is_msg34(type) && m->remote.extrainfo.size) {
802 m->signing_key_index=buf_unprepend_uint8(&m->remote.extrainfo);
804 m->signing_key_index=0;
806 if (!unpick_name(msg,&m->local)) return False;
807 if (type==LABEL_PROD) {
811 CHECK_AVAIL(msg,NONCELEN);
812 m->nR=buf_unprepend(msg,NONCELEN);
813 if (type==LABEL_MSG1) {
817 CHECK_AVAIL(msg,NONCELEN);
818 m->nL=buf_unprepend(msg,NONCELEN);
819 if (type==LABEL_MSG2) {
823 if (MSGMAJOR(type) == 3) do {
824 minor = MSGMINOR(type);
825 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
826 if (minor < (minminor)) \
827 m->capab_##kind##num = (dflt); \
829 CHECK_AVAIL(msg, 1); \
830 m->capab_##kind##num = buf_unprepend_uint8(msg); \
833 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
834 #undef MAYBE_READ_CAP
837 m->pklen=buf_unprepend_uint16(msg);
838 CHECK_AVAIL(msg,m->pklen);
839 m->pk=buf_unprepend(msg,m->pklen);
840 m->hashlen=msg->start-m->hashstart;
842 if (m->signing_key_index < 0 ||
843 m->signing_key_index >= st->peerkeys_kex->nkeys) {
846 struct sigpubkey_if *pubkey=
847 st->peerkeys_kex->keys[m->signing_key_index].pubkey;
848 if (!pubkey->unpick(pubkey->st,msg,&m->sig)) {
857 static bool_t name_matches(const struct parsedname *nm, const char *expected)
859 int expected_len=strlen(expected);
861 nm->len == expected_len &&
862 !memcmp(nm->name, expected, expected_len);
865 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
868 if (type==LABEL_MSG1) return True;
870 /* Check that the site names and our nonce have been sent
871 back correctly, and then store our peer's nonce. */
872 if (!name_matches(&m->remote,st->remotename)) {
873 *error="wrong remote site name";
876 if (!name_matches(&m->local,st->localname)) {
877 *error="wrong local site name";
880 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
881 *error="wrong locally-generated nonce";
884 if (type==LABEL_MSG2) return True;
885 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
886 *error="wrong remotely-generated nonce";
889 /* MSG3 has complicated rules about capabilities, which are
890 * handled in process_msg3. */
891 if (MSGMAJOR(type) == 3) return True;
892 if (m->remote_capabilities!=st->remote_capabilities) {
893 *error="remote capabilities changed";
896 if (type==LABEL_MSG4) return True;
897 *error="unknown message type";
901 static void peerkeys_maybe_incorporate(struct site *st, const char *file,
902 const char *whatmore,
905 struct peer_keyset *atsuffix=
906 keyset_load(file,&st->scratch,st->log,logcl_enoent,st->defhash);
907 if (!atsuffix) return;
909 if (st->peerkeys_current &&
910 serial_cmp(atsuffix->serial,st->peerkeys_current->serial) <= 0) {
911 slog(st,LOG_SIGKEYS,"keys from %s%s are older, discarding",
913 keyset_dispose(&atsuffix);
915 if (r) slog(st,LOG_ERROR,"failed to remove old key update %s: %s\n",
916 st->peerkeys_tmpl.buffer,strerror(errno));
919 slog(st,LOG_SIGKEYS,"keys from %s%s are newer, installing",
921 keyset_dispose(&st->peerkeys_current);
922 st->peerkeys_current=atsuffix;
923 int r=rename(file,st->peerkeys_path);
924 if (r) slog(st,LOG_ERROR,"failed to install key update %s as %s: %s\n",
925 st->peerkeys_tmpl.buffer,st->peerkeys_path,
930 static void peerkeys_check_for_update(struct site *st)
932 if (!st->peerkeys_path) return;
934 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~proc");
935 peerkeys_maybe_incorporate(st,st->peerkeys_tmpl.buffer,
936 " (found old update)",
939 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~update");
940 const char *inputp=st->peerkeys_tmpl.buffer;
941 if (access(inputp,R_OK)) {
943 slog(st,LOG_ERROR,"cannot access peer key update file %s\n",
948 buffer_init(&st->scratch,0);
949 BUF_ADD_BYTES(append,&st->scratch,
950 st->peerkeys_tmpl.buffer,
951 strlen(st->peerkeys_tmpl.buffer)+1);
952 inputp=st->scratch.start;
954 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~proc");
955 const char *oursp=st->peerkeys_tmpl.buffer;
957 int r=rename(inputp,oursp);
959 slog(st,LOG_ERROR,"failed to claim key update file %s as %s: %s",
960 inputp,oursp,strerror(errno));
964 peerkeys_maybe_incorporate(st,oursp," (update)",M_ERR);
968 static bool_t kex_init(struct site *st)
970 keyset_dispose(&st->peerkeys_kex);
971 peerkeys_check_for_update(st);
972 if (!st->peerkeys_current) {
973 slog(st,LOG_SETUP_INIT,"no peer public keys, abandoning key setup");
976 st->peerkeys_kex = keyset_dup(st->peerkeys_current);
977 st->random->generate(st->random->st,NONCELEN,st->localN);
981 static bool_t generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
984 generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
987 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
988 const struct comm_addr *src,
991 /* We've already determined we're in an appropriate state to
992 process an incoming MSG1, and that the MSG1 has correct values
995 st->setup_session_id=m->source;
996 st->remote_capabilities=m->remote_capabilities;
997 memcpy(st->remoteN,m->nR,NONCELEN);
1001 static bool_t generate_msg2(struct site *st,
1002 const struct msg *prompt_may_be_null)
1005 generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
1008 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
1009 const struct comm_addr *src,
1010 struct msg *m /* returned */)
1014 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
1015 if (!check_msg(st,LABEL_MSG2,m,&err)) {
1016 slog(st,LOG_SEC,"msg2: %s",err);
1019 st->setup_session_id=m->source;
1020 st->remote_capabilities=m->remote_capabilities;
1022 /* Select the transform to use */
1024 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
1025 if (!remote_crypto_caps)
1026 /* old secnets only had this one transform */
1027 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
1029 #define CHOOSE_CRYPTO(kind, whats) do { \
1030 struct kind##_if *iface; \
1031 uint32_t bit, ours = 0; \
1033 for (i= 0; i < st->n##kind##s; i++) { \
1034 iface=st->kind##s[i]; \
1035 bit = 1UL << iface->capab_bit; \
1036 if (bit & remote_crypto_caps) goto kind##_found; \
1039 slog(st,LOG_ERROR,"no " whats " in common" \
1040 " (us %#"PRIx32"; them: %#"PRIx32")", \
1041 st->local_capabilities & ours, remote_crypto_caps); \
1044 st->chosen_##kind = iface; \
1047 CHOOSE_CRYPTO(transform, "transforms");
1049 #undef CHOOSE_CRYPTO
1051 memcpy(st->remoteN,m->nR,NONCELEN);
1055 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
1057 /* Now we have our nonce and their nonce. Think of a secret key,
1058 and create message number 3. */
1059 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1060 return generate_msg(st,
1061 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
1064 "site:MSG3",prompt);
1067 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
1069 /* Check signature and store g^x mod m */
1072 if (m->signing_key_index >= 0) {
1073 if (m->signing_key_index >= st->peerkeys_kex->nkeys)
1075 ki=m->signing_key_index;
1077 for (ki=0; ki<st->peerkeys_kex->nkeys; ki++)
1078 if (sigkeyid_equal(&keyid_zero,&st->peerkeys_kex->keys[ki].id))
1082 "peer signed with keyid zero, which we do not accept");
1086 struct sigpubkey_if *pubkey=st->peerkeys_kex->keys[ki].pubkey;
1088 if (!pubkey->check(pubkey->st,
1089 m->hashstart,m->hashlen,
1091 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
1095 st->remote_adv_mtu=m->remote_mtu;
1100 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
1101 const struct comm_addr *src, uint32_t msgtype,
1102 struct msg *m /* returned */)
1107 case CASES_MSG3_KNOWN: break;
1111 if (!unpick_msg(st,msgtype,msg3,m)) return False;
1112 if (!check_msg(st,msgtype,m,&err)) {
1113 slog(st,LOG_SEC,"msg3: %s",err);
1116 uint32_t capab_adv_late = m->remote_capabilities
1117 & ~st->remote_capabilities & st->early_capabilities;
1118 if (capab_adv_late) {
1119 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
1120 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
1121 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
1125 #define CHOSE_CRYPTO(kind, what) do { \
1126 struct kind##_if *iface; \
1128 for (i=0; i<st->n##kind##s; i++) { \
1129 iface=st->kind##s[i]; \
1130 if (iface->capab_bit == m->capab_##kind##num) \
1131 goto kind##_found; \
1133 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
1134 m->capab_##kind##num); \
1137 st->chosen_##kind=iface; \
1140 CHOSE_CRYPTO(transform, "transform");
1144 if (!process_msg3_msg4(st,m))
1147 /* Update our idea of the remote site's capabilities, now that we've
1148 * verified that its message was authentic.
1150 * Our previous idea of the remote site's capabilities came from the
1151 * unauthenticated MSG1. We've already checked that this new message
1152 * doesn't change any of the bits we relied upon in the past, but it may
1153 * also have set additional capability bits. We simply throw those away
1154 * now, and use the authentic capabilities from this MSG3. */
1155 st->remote_capabilities=m->remote_capabilities;
1157 /* Terminate their DH public key with a '0' */
1159 /* Invent our DH secret key */
1160 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1162 /* Generate the shared key and set up the transform */
1163 if (!set_new_transform(st,m->pk)) return False;
1168 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
1170 /* We have both nonces, their public key and our private key. Generate
1171 our public key, sign it and send it to them. */
1172 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
1175 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
1176 const struct comm_addr *src,
1177 struct msg *m /* returned */)
1181 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
1182 if (!check_msg(st,LABEL_MSG4,m,&err)) {
1183 slog(st,LOG_SEC,"msg4: %s",err);
1187 if (!process_msg3_msg4(st,m))
1190 /* Terminate their DH public key with a '0' */
1193 /* Generate the shared key and set up the transform */
1194 if (!set_new_transform(st,m->pk)) return False;
1205 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1208 CHECK_AVAIL(msg0,4);
1209 m->dest=buf_unprepend_uint32(msg0);
1210 CHECK_AVAIL(msg0,4);
1211 m->source=buf_unprepend_uint32(msg0);
1212 CHECK_AVAIL(msg0,4);
1213 m->type=buf_unprepend_uint32(msg0);
1215 /* Leaves transformed part of buffer untouched */
1218 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1220 cstring_t transform_err;
1222 BUF_ALLOC(&st->buffer,"site:MSG5");
1223 /* We are going to add four words to the message */
1224 buffer_init(&st->buffer,calculate_max_start_pad());
1225 /* Give the netlink code an opportunity to put its own stuff in the
1226 message (configuration information, etc.) */
1227 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1228 if (call_transform_forwards(st,st->new_transform,
1229 &st->buffer,&transform_err))
1231 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1232 buf_prepend_uint32(&st->buffer,st->index);
1233 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1235 st->retries=st->setup_retries;
1239 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1240 const struct comm_addr *src,
1241 struct transform_inst_if *transform)
1244 cstring_t transform_err;
1246 if (!unpick_msg0(st,msg5,&m)) return False;
1248 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1249 /* There's a problem */
1250 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1253 /* Buffer should now contain untransformed PING packet data */
1254 CHECK_AVAIL(msg5,4);
1255 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1256 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1259 /* Older versions of secnet used to write some config data here
1260 * which we ignore. So we don't CHECK_EMPTY */
1264 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1265 uint32_t session_id)
1267 cstring_t transform_err;
1269 BUF_ALLOC(&st->buffer,"site:MSG6");
1270 /* We are going to add four words to the message */
1271 buffer_init(&st->buffer,calculate_max_start_pad());
1272 /* Give the netlink code an opportunity to put its own stuff in the
1273 message (configuration information, etc.) */
1274 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1275 transform_apply_return problem =
1276 call_transform_forwards(st,transform,
1277 &st->buffer,&transform_err);
1279 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1280 buf_prepend_uint32(&st->buffer,st->index);
1281 buf_prepend_uint32(&st->buffer,session_id);
1284 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1286 if (!is_transform_valid(st->new_transform))
1288 create_msg6(st,st->new_transform,st->setup_session_id);
1289 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1293 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1294 const struct comm_addr *src)
1297 cstring_t transform_err;
1299 if (!unpick_msg0(st,msg6,&m)) return False;
1301 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1302 /* There's a problem */
1303 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1306 /* Buffer should now contain untransformed PING packet data */
1307 CHECK_AVAIL(msg6,4);
1308 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1309 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1312 /* Older versions of secnet used to write some config data here
1313 * which we ignore. So we don't CHECK_EMPTY */
1317 static transform_apply_return
1318 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1319 const struct comm_addr *src)
1321 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1323 transform_apply_return problem;
1325 if (!unpick_msg0(st,msg0,&m)) return False;
1327 /* Keep a copy so we can try decrypting it with multiple keys */
1328 buffer_copy(&st->scratch, msg0);
1330 problem = call_transform_reverse(st,st->current.transform,
1331 msg0,&transform_err);
1333 if (!st->auxiliary_is_new)
1334 delete_one_key(st,&st->auxiliary_key,
1335 "peer has used new key","auxiliary key",LOG_SEC);
1338 if (transform_apply_return_badseq(problem))
1341 buffer_copy(msg0, &st->scratch);
1342 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1345 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1346 if (st->auxiliary_is_new) {
1347 /* We previously timed out in state SENTMSG5 but it turns
1348 * out that our peer did in fact get our MSG5 and is
1349 * using the new key. So we should switch to it too. */
1350 /* This is a bit like activate_new_key. */
1353 st->current=st->auxiliary_key;
1354 st->auxiliary_key=t;
1356 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1357 "previous key",LOG_SEC);
1358 st->auxiliary_is_new=0;
1359 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1363 if (transform_apply_return_badseq(problem))
1366 if (st->state==SITE_SENTMSG5) {
1367 buffer_copy(msg0, &st->scratch);
1368 problem = call_transform_reverse(st,st->new_transform,
1371 /* It looks like we didn't get the peer's MSG6 */
1372 /* This is like a cut-down enter_new_state(SITE_RUN) */
1373 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1374 BUF_FREE(&st->buffer);
1376 activate_new_key(st);
1377 return 0; /* do process the data in this packet */
1379 if (transform_apply_return_badseq(problem))
1383 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1384 transform_err,auxkey_err,newkey_err);
1385 initiate_key_setup(st,"incoming message would not decrypt",0);
1386 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1391 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1396 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1397 const struct comm_addr *src)
1400 transform_apply_return problem;
1402 problem = decrypt_msg0(st,msg0,src);
1403 if (problem==transform_apply_seqdupe) {
1404 /* We recently received another copy of this packet, maybe due
1405 * to polypath. That's not a problem; indeed, for the
1406 * purposes of transport address management it is a success.
1407 * But we don't want to process the packet. */
1408 transport_data_msgok(st,src);
1414 CHECK_AVAIL(msg0,4);
1415 type=buf_unprepend_uint32(msg0);
1418 /* We must forget about the current session. */
1419 delete_keys(st,"request from peer",LOG_SEC);
1420 /* probably, the peer is shutting down, and this is going to fail,
1421 * but we need to be trying to bring the link up again */
1423 initiate_key_setup(st,"peer requested key teardown",0);
1426 /* Deliver to netlink layer */
1427 st->netlink->deliver(st->netlink->st,msg0);
1428 transport_data_msgok(st,src);
1429 /* See whether we should start negotiating a new key */
1430 if (st->now > st->renegotiate_key_time)
1431 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1434 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1441 static void dump_packet(struct site *st, struct buffer_if *buf,
1442 const struct comm_addr *addr, bool_t incoming,
1445 uint32_t dest=get_uint32(buf->start);
1446 uint32_t source=get_uint32(buf->start+4);
1447 uint32_t msgtype=get_uint32(buf->start+8);
1449 if (st->log_events & LOG_DUMP)
1450 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1451 st->tunname,incoming?"incoming":"outgoing",
1452 dest,source,msgtype,comm_addr_to_string(addr),
1456 static bool_t comm_addr_sendmsg(struct site *st,
1457 const struct comm_addr *dest,
1458 struct buffer_if *buf)
1461 struct comm_clientinfo *commclientinfo = 0;
1463 for (i=0; i < st->ncomms; i++) {
1464 if (st->comms[i] == dest->comm) {
1465 commclientinfo = st->commclientinfos[i];
1469 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1472 static uint32_t site_status(void *st)
1477 static bool_t send_msg(struct site *st)
1479 if (st->retries>0) {
1480 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1481 st->timeout=st->now+st->setup_retry_interval;
1484 } else if (st->state==SITE_SENTMSG5) {
1485 logtimeout(st,"timed out sending MSG5, stashing new key");
1486 /* We stash the key we have produced, in case it turns out that
1487 * our peer did see our MSG5 after all and starts using it. */
1488 /* This is a bit like some of activate_new_key */
1489 struct transform_inst_if *t;
1490 t=st->auxiliary_key.transform;
1491 st->auxiliary_key.transform=st->new_transform;
1492 st->new_transform=t;
1493 dispose_transform(&st->new_transform);
1495 st->auxiliary_is_new=1;
1496 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1497 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1498 st->auxiliary_key.remote_session_id=st->setup_session_id;
1500 enter_state_wait(st);
1503 logtimeout(st,"timed out sending key setup packet "
1504 "(in state %s)",state_name(st->state));
1505 enter_state_wait(st);
1510 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1511 int stored_naddrs, int all_naddrs,
1512 const char *address, const char *failwhy)
1514 struct site *st=sst;
1516 if (!stored_naddrs) {
1517 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1519 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1520 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1522 int space=st->transport_peers_max-st->resolving_n_results_stored;
1523 int n_tocopy=MIN(stored_naddrs,space);
1524 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1527 st->resolving_n_results_stored += n_tocopy;
1528 st->resolving_n_results_all += all_naddrs;
1531 decrement_resolving_count(st,1);
1534 static void decrement_resolving_count(struct site *st, int by)
1536 assert(st->resolving_count>0);
1537 st->resolving_count-=by;
1539 if (st->resolving_count)
1542 /* OK, we are done with them all. Handle combined results. */
1544 const struct comm_addr *addrs=st->resolving_results;
1545 int naddrs=st->resolving_n_results_stored;
1546 assert(naddrs<=st->transport_peers_max);
1549 if (naddrs != st->resolving_n_results_all) {
1550 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1551 " yielded too many results (%d > %d), some ignored",
1552 st->resolving_n_results_all, naddrs);
1554 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1555 naddrs, iaddr_to_string(&addrs[0].ia));;
1558 switch (st->state) {
1560 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1561 enter_new_state(st,SITE_SENTMSG1,0);
1563 /* Can't figure out who to try to to talk to */
1564 slog(st,LOG_SETUP_INIT,
1565 "key exchange failed: cannot find peer address");
1566 enter_state_run(st);
1569 case SITE_SENTMSG1: case SITE_SENTMSG2:
1570 case SITE_SENTMSG3: case SITE_SENTMSG4:
1573 /* We start using the address immediately for data too.
1574 * It's best to store it in st->peers now because we might
1575 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1576 * the new key (without updating the data peer addrs). */
1577 transport_resolve_complete(st,addrs,naddrs);
1578 } else if (st->local_mobile) {
1579 /* We can't let this rest because we may have a peer
1580 * address which will break in the future. */
1581 slog(st,LOG_SETUP_INIT,"resolution failed: "
1582 "abandoning key exchange");
1583 enter_state_wait(st);
1585 slog(st,LOG_SETUP_INIT,"resolution failed: "
1586 " continuing to use source address of peer's packets"
1587 " for key exchange and ultimately data");
1592 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1593 " updating peer address(es)");
1594 transport_resolve_complete_tardy(st,addrs,naddrs);
1595 } else if (st->local_mobile) {
1596 /* Not very good. We should queue (another) renegotiation
1597 * so that we can update the peer address. */
1598 st->key_renegotiate_time=st->now+wait_timeout(st);
1600 slog(st,LOG_SETUP_INIT,"resolution failed: "
1601 " continuing to use source address of peer's packets");
1611 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1612 const struct comm_addr *prod_hint)
1614 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1615 if (st->state!=SITE_RUN) return False;
1616 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1617 if (st->addresses) {
1618 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1619 return enter_state_resolve(st);
1620 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1621 return enter_new_state(st,SITE_SENTMSG1,0);
1623 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1627 static void activate_new_key(struct site *st)
1629 struct transform_inst_if *t;
1631 /* We have three transform instances, which we swap between old,
1633 t=st->auxiliary_key.transform;
1634 st->auxiliary_key.transform=st->current.transform;
1635 st->current.transform=st->new_transform;
1636 st->new_transform=t;
1637 dispose_transform(&st->new_transform);
1640 st->auxiliary_is_new=0;
1641 st->auxiliary_key.key_timeout=st->current.key_timeout;
1642 st->current.key_timeout=st->now+st->key_lifetime;
1643 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1644 transport_peers_copy(st,&st->peers,&st->setup_peers);
1645 st->current.remote_session_id=st->setup_session_id;
1647 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1648 * But their mtu be unspecified, in which case we just use ours. */
1649 uint32_t intersite_mtu=
1650 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1651 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1653 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1654 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1655 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1656 enter_state_run(st);
1659 static void delete_one_key(struct site *st, struct data_key *key,
1660 cstring_t reason, cstring_t which, uint32_t loglevel)
1662 if (!is_transform_valid(key->transform)) return;
1663 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1664 dispose_transform(&key->transform);
1668 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1670 if (current_valid(st)) {
1671 slog(st,loglevel,"session closed (%s)",reason);
1673 delete_one_key(st,&st->current,0,0,0);
1674 set_link_quality(st);
1676 delete_one_key(st,&st->auxiliary_key,0,0,0);
1679 static void state_assert(struct site *st, bool_t ok)
1681 if (!ok) fatal("site:state_assert");
1684 static void enter_state_stop(struct site *st)
1686 st->state=SITE_STOP;
1688 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1689 dispose_transform(&st->new_transform);
1692 static void set_link_quality(struct site *st)
1695 if (current_valid(st))
1696 quality=LINK_QUALITY_UP;
1697 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1698 quality=LINK_QUALITY_DOWN;
1699 else if (st->addresses)
1700 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1701 else if (transport_peers_valid(&st->peers))
1702 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1704 quality=LINK_QUALITY_DOWN;
1706 st->netlink->set_quality(st->netlink->st,quality);
1709 static void enter_state_run(struct site *st)
1711 slog(st,LOG_STATE,"entering state RUN%s",
1712 current_valid(st) ? " (keyed)" : " (unkeyed)");
1716 st->setup_session_id=0;
1717 transport_peers_clear(st,&st->setup_peers);
1718 keyset_dispose(&st->peerkeys_kex);
1719 FILLZERO(st->localN);
1720 FILLZERO(st->remoteN);
1721 dispose_transform(&st->new_transform);
1722 memset(st->dhsecret,0,st->dh->len);
1723 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1724 set_link_quality(st);
1726 if (st->keepalive && !current_valid(st))
1727 initiate_key_setup(st, "keepalive", 0);
1730 static bool_t ensure_resolving(struct site *st)
1732 /* Reentrancy hazard: may call site_resolve_callback and hence
1733 * enter_new_state, enter_state_* and generate_msg*. */
1734 if (st->resolving_count)
1737 assert(st->addresses);
1739 /* resolver->request might reentrantly call site_resolve_callback
1740 * which will decrement st->resolving, so we need to increment it
1741 * twice beforehand to prevent decrement from thinking we're
1742 * finished, and decrement it ourselves. Alternatively if
1743 * everything fails then there are no callbacks due and we simply
1744 * set it to 0 and return false.. */
1745 st->resolving_n_results_stored=0;
1746 st->resolving_n_results_all=0;
1747 st->resolving_count+=2;
1748 const char **addrp=st->addresses;
1749 const char *address;
1751 for (; (address=*addrp++); ) {
1752 bool_t ok = st->resolver->request(st->resolver->st,address,
1753 st->remoteport,st->comms[0],
1754 site_resolve_callback,st);
1756 st->resolving_count++;
1760 st->resolving_count=0;
1763 decrement_resolving_count(st,2);
1767 static bool_t enter_state_resolve(struct site *st)
1769 /* Reentrancy hazard! See ensure_resolving. */
1770 state_assert(st,st->state==SITE_RUN);
1771 slog(st,LOG_STATE,"entering state RESOLVE");
1772 st->state=SITE_RESOLVE;
1773 return ensure_resolving(st);
1776 static bool_t enter_new_state(struct site *st, uint32_t next,
1777 const struct msg *prompt
1778 /* may be 0 for SENTMSG1 */)
1780 bool_t (*gen)(struct site *st, const struct msg *prompt);
1783 slog(st,LOG_STATE,"entering state %s",state_name(next));
1786 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1787 if (!kex_init(st)) return False;
1789 st->msg1_crossed_logged = False;
1792 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1793 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1794 if (!kex_init(st)) return False;
1798 state_assert(st,st->state==SITE_SENTMSG1);
1799 BUF_FREE(&st->buffer);
1803 state_assert(st,st->state==SITE_SENTMSG2);
1804 BUF_FREE(&st->buffer);
1808 state_assert(st,st->state==SITE_SENTMSG3);
1809 BUF_FREE(&st->buffer);
1813 state_assert(st,st->state==SITE_SENTMSG4);
1814 BUF_FREE(&st->buffer);
1819 fatal("enter_new_state(%s): invalid new state",state_name(next));
1823 if (hacky_par_start_failnow()) return False;
1825 r= gen(st,prompt) && send_msg(st);
1828 st->setup_retries, st->setup_retry_interval,
1833 if (next==SITE_RUN) {
1834 BUF_FREE(&st->buffer); /* Never reused */
1835 st->timeout=0; /* Never retransmit */
1836 activate_new_key(st);
1840 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1841 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1842 in either state, and enter_state_wait() will
1844 enter_state_wait(st);
1848 /* msg7 tells our peer that we're about to forget our key */
1849 static bool_t send_msg7(struct site *st, cstring_t reason)
1851 cstring_t transform_err;
1853 if (current_valid(st) && st->buffer.free
1854 && transport_peers_valid(&st->peers)) {
1855 BUF_ALLOC(&st->buffer,"site:MSG7");
1856 buffer_init(&st->buffer,calculate_max_start_pad());
1857 buf_append_uint32(&st->buffer,LABEL_MSG7);
1858 buf_append_string(&st->buffer,reason);
1859 if (call_transform_forwards(st, st->current.transform,
1860 &st->buffer, &transform_err))
1862 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1863 buf_prepend_uint32(&st->buffer,st->index);
1864 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1865 transport_xmit(st,&st->peers,&st->buffer,True);
1866 BUF_FREE(&st->buffer);
1873 /* We go into this state if our peer becomes uncommunicative. Similar to
1874 the "stop" state, we forget all session keys for a while, before
1875 re-entering the "run" state. */
1876 static void enter_state_wait(struct site *st)
1878 slog(st,LOG_STATE,"entering state WAIT");
1879 st->timeout=st->now+wait_timeout(st);
1880 st->state=SITE_WAIT;
1881 set_link_quality(st);
1882 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1883 /* XXX Erase keys etc. */
1886 static void generate_prod(struct site *st, struct buffer_if *buf)
1889 buf_append_uint32(buf,0);
1890 buf_append_uint32(buf,0);
1891 buf_append_uint32(buf,LABEL_PROD);
1892 buf_append_string(buf,st->localname);
1893 buf_append_string(buf,st->remotename);
1896 static void generate_send_prod(struct site *st,
1897 const struct comm_addr *source)
1899 if (!st->allow_send_prod) return; /* too soon */
1900 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1901 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1903 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1904 st->allow_send_prod=0;
1905 generate_prod(st,&st->scratch);
1906 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1907 dump_packet(st,&st->scratch,source,False,ok);
1910 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1913 int64_t offset=timeout-*now;
1914 if (offset<0) offset=0;
1915 if (offset>INT_MAX) offset=INT_MAX;
1916 if (*timeout_io<0 || offset<*timeout_io)
1921 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1924 struct site *st=sst;
1926 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1929 /* Work out when our next timeout is. The earlier of 'timeout' or
1930 'current.key_timeout'. A stored value of '0' indicates no timeout
1932 site_settimeout(st->timeout, timeout_io);
1933 site_settimeout(st->current.key_timeout, timeout_io);
1934 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1936 return 0; /* success */
1939 static void check_expiry(struct site *st, struct data_key *key,
1942 if (key->key_timeout && *now>key->key_timeout) {
1943 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1947 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1948 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1950 struct site *st=sst;
1953 if (st->timeout && *now>st->timeout) {
1955 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1956 if (!hacky_par_start_failnow())
1958 } else if (st->state==SITE_WAIT) {
1959 enter_state_run(st);
1961 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1965 check_expiry(st,&st->current,"current key");
1966 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1969 /* This function is called by the netlink device to deliver packets
1970 intended for the remote network. The packet is in "raw" wire
1971 format, but is guaranteed to be word-aligned. */
1972 static void site_outgoing(void *sst, struct buffer_if *buf)
1974 struct site *st=sst;
1975 cstring_t transform_err;
1977 if (st->state==SITE_STOP) {
1982 st->allow_send_prod=1;
1984 /* In all other states we consider delivering the packet if we have
1985 a valid key and a valid address to send it to. */
1986 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1987 /* Transform it and send it */
1989 buf_prepend_uint32(buf,LABEL_MSG9);
1990 if (call_transform_forwards(st, st->current.transform,
1991 buf, &transform_err))
1993 buf_prepend_uint32(buf,LABEL_MSG0);
1994 buf_prepend_uint32(buf,st->index);
1995 buf_prepend_uint32(buf,st->current.remote_session_id);
1996 transport_xmit(st,&st->peers,buf,False);
2003 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
2005 initiate_key_setup(st,"outgoing packet",0);
2008 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
2009 uint32_t type, struct msg *m,
2010 struct priomsg *whynot)
2011 /* For packets which are identified by the local and remote names.
2012 * If it has our name and our peer's name in it it's for us. */
2014 struct buffer_if buf[1];
2015 buffer_readonly_clone(buf,buf_in);
2017 if (!unpick_msg(st,type,buf,m)) {
2018 priomsg_update_fixed(whynot, comm_notify_whynot_unpick, "malformed");
2021 #define NAME_MATCHES(lr) \
2022 if (!name_matches(&m->lr, st->lr##name)) { \
2023 if (priomsg_update_fixed(whynot, comm_notify_whynot_name_##lr, \
2024 "unknown " #lr " name: ")) { \
2025 truncmsg_add_packet_string(&whynot->m, m->lr.len, m->lr.name); \
2029 NAME_MATCHES(remote);
2030 NAME_MATCHES(local );
2036 static bool_t we_have_priority(struct site *st, const struct msg *m) {
2037 if (st->local_capabilities & m->remote_capabilities &
2038 CAPAB_PRIORITY_MOBILE) {
2039 if (st->local_mobile) return True;
2040 if (st-> peer_mobile) return False;
2042 return st->our_name_later;
2045 static bool_t setup_late_msg_ok(struct site *st,
2046 const struct buffer_if *buf_in,
2048 const struct comm_addr *source,
2049 struct msg *m /* returned */) {
2050 /* For setup packets which seem from their type like they are
2051 * late. Maybe they came via a different path. All we do is make
2052 * a note of the sending address, iff they look like they are part
2053 * of the current key setup attempt. */
2054 if (!named_for_us(st,buf_in,msgtype,m,0))
2055 /* named_for_us calls unpick_msg which gets the nonces */
2057 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
2058 !consttime_memeq(m->nL,st->localN, NONCELEN))
2059 /* spoof ? from stale run ? who knows */
2061 transport_setup_msgok(st,source);
2065 /* This function is called by the communication device to deliver
2066 packets from our peers.
2067 It should return True if the packet is recognised as being for
2068 this current site instance (and should therefore not be processed
2069 by other sites), even if the packet was otherwise ignored. */
2070 static bool_t site_incoming(void *sst, struct buffer_if *buf,
2071 const struct comm_addr *source,
2072 struct priomsg *whynot)
2074 struct site *st=sst;
2076 if (buf->size < 12) return False;
2078 uint32_t dest=get_uint32(buf->start);
2079 uint32_t msgtype=get_uint32(buf->start+8);
2081 /* initialised by named_for_us, or process_msgN for N!=1 */
2083 if (msgtype==LABEL_MSG1) {
2084 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2086 /* It's a MSG1 addressed to us. Decide what to do about it. */
2087 dump_packet(st,buf,source,True,True);
2088 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
2089 st->state==SITE_WAIT) {
2090 /* We should definitely process it */
2091 transport_compute_setupinit_peers(st,0,0,source);
2092 if (process_msg1(st,buf,source,&msg)) {
2093 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
2094 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
2095 if (entered && st->addresses && st->local_mobile)
2096 /* We must do this as the very last thing, because
2097 the resolver callback might reenter us. */
2098 ensure_resolving(st);
2100 slog(st,LOG_ERROR,"failed to process incoming msg1");
2104 } else if (st->state==SITE_SENTMSG1) {
2105 /* We've just sent a message 1! They may have crossed on
2106 the wire. If we have priority then we ignore the
2107 incoming one, otherwise we process it as usual. */
2108 if (we_have_priority(st,&msg)) {
2110 if (!st->msg1_crossed_logged++)
2111 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
2112 "priority => ignore incoming msg1");
2115 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
2116 "priority => use incoming msg1");
2117 if (process_msg1(st,buf,source,&msg)) {
2118 BUF_FREE(&st->buffer); /* Free our old message 1 */
2119 transport_setup_msgok(st,source);
2120 enter_new_state(st,SITE_SENTMSG2,&msg);
2122 slog(st,LOG_ERROR,"failed to process an incoming "
2123 "crossed msg1 (we have low priority)");
2128 } else if (st->state==SITE_SENTMSG2 ||
2129 st->state==SITE_SENTMSG4) {
2130 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
2131 /* We are ahead in the protocol, but that msg1 had the
2132 * peer's nonce so presumably it is from this key
2133 * exchange run, via a slower route */
2134 transport_setup_msgok(st,source);
2136 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
2141 /* The message 1 was received at an unexpected stage of the
2142 key setup. Well, they lost the race. */
2143 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
2147 if (msgtype==LABEL_PROD) {
2148 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2150 dump_packet(st,buf,source,True,True);
2151 if (st->state!=SITE_RUN) {
2152 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
2153 } else if (current_valid(st)) {
2154 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
2156 initiate_key_setup(st,"peer sent PROD packet",source);
2161 if (dest==st->index) {
2162 /* Explicitly addressed to us */
2163 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
2166 /* If the source is our current peer then initiate a key setup,
2167 because our peer's forgotten the key */
2168 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
2170 initiated = initiate_key_setup(st,"received a NAK",source);
2171 if (!initiated) generate_send_prod(st,source);
2173 slog(st,LOG_SEC,"bad incoming NAK");
2177 process_msg0(st,buf,source);
2180 /* Setup packet: should not have been explicitly addressed
2182 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2185 /* Setup packet: expected only in state SENTMSG1 */
2186 if (st->state!=SITE_SENTMSG1) {
2187 if ((st->state==SITE_SENTMSG3 ||
2188 st->state==SITE_SENTMSG5) &&
2189 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2191 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
2192 } else if (process_msg2(st,buf,source,&msg)) {
2193 transport_setup_msgok(st,source);
2194 enter_new_state(st,SITE_SENTMSG3,&msg);
2196 slog(st,LOG_SEC,"invalid MSG2");
2199 case CASES_MSG3_KNOWN:
2200 /* Setup packet: expected only in state SENTMSG2 */
2201 if (st->state!=SITE_SENTMSG2) {
2202 if ((st->state==SITE_SENTMSG4) &&
2203 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2205 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2206 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2207 transport_setup_msgok(st,source);
2208 enter_new_state(st,SITE_SENTMSG4,&msg);
2210 slog(st,LOG_SEC,"invalid MSG3");
2214 /* Setup packet: expected only in state SENTMSG3 */
2215 if (st->state!=SITE_SENTMSG3) {
2216 if ((st->state==SITE_SENTMSG5) &&
2217 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2219 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2220 } else if (process_msg4(st,buf,source,&msg)) {
2221 transport_setup_msgok(st,source);
2222 enter_new_state(st,SITE_SENTMSG5,&msg);
2224 slog(st,LOG_SEC,"invalid MSG4");
2228 /* Setup packet: expected only in state SENTMSG4 */
2229 /* (may turn up in state RUN if our return MSG6 was lost
2230 and the new key has already been activated. In that
2231 case we discard it. The peer will realise that we
2232 are using the new key when they see our data packets.
2233 Until then the peer's data packets to us get discarded. */
2234 if (st->state==SITE_SENTMSG4) {
2235 if (process_msg5(st,buf,source,st->new_transform)) {
2236 transport_setup_msgok(st,source);
2237 enter_new_state(st,SITE_RUN,&msg);
2239 slog(st,LOG_SEC,"invalid MSG5");
2241 } else if (st->state==SITE_RUN) {
2242 if (process_msg5(st,buf,source,st->current.transform)) {
2243 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2244 transport_setup_msgok(st,source);
2245 create_msg6(st,st->current.transform,
2246 st->current.remote_session_id);
2247 transport_xmit(st,&st->peers,&st->buffer,True);
2248 BUF_FREE(&st->buffer);
2250 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2253 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2257 /* Setup packet: expected only in state SENTMSG5 */
2258 if (st->state!=SITE_SENTMSG5) {
2259 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2260 } else if (process_msg6(st,buf,source)) {
2261 BUF_FREE(&st->buffer); /* Free message 5 */
2262 transport_setup_msgok(st,source);
2263 activate_new_key(st);
2265 slog(st,LOG_SEC,"invalid MSG6");
2269 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2277 priomsg_update_fixed(whynot, comm_notify_whynot_general,
2278 "not MSG1 or PROD; unknown dest index");
2282 static void site_control(void *vst, bool_t run)
2284 struct site *st=vst;
2285 if (run) enter_state_run(st);
2286 else enter_state_stop(st);
2289 static void site_phase_hook(void *sst, uint32_t newphase)
2291 struct site *st=sst;
2293 /* The program is shutting down; tell our peer */
2294 send_msg7(st,"shutting down");
2297 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2299 struct site *st=sst;
2300 dispose_transform(&st->current.transform);
2301 dispose_transform(&st->auxiliary_key.transform);
2302 dispose_transform(&st->new_transform);
2303 /* Not much point overwiting the signing key, since we loaded it
2304 from disk, and it is only valid prospectively if at all,
2306 /* XXX it would be best to overwrite the DH state, because that
2307 _is_ relevant to forward secrecy. However we have no
2308 convenient interface for doing that and in practice gmp has
2309 probably dribbled droppings all over the malloc arena. A good
2310 way to fix this would be to have a privsep child for asymmetric
2311 crypto operations, but that's a task for another day. */
2314 static void setup_sethash(struct site *st, dict_t *dict,
2316 sig_sethash_fn *sethash, void *sigkey_st) {
2318 cfgfatal(loc,"site","other settings imply `hash' key is needed");
2319 sethash(sigkey_st,st->defhash);
2321 #define SETUP_SETHASH(k) do{ \
2323 setup_sethash(st,dict,loc, (k)->sethash,(k)->st); \
2326 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2329 static uint32_t index_sequence;
2337 st->cl.description="site";
2338 st->cl.type=CL_SITE;
2340 st->cl.interface=&st->ops;
2342 st->ops.control=site_control;
2343 st->ops.status=site_status;
2344 st->peerkeys_path=0;
2345 st->peerkeys_tmpl.buffer=0;
2346 st->peerkeys_current=st->peerkeys_kex=0;
2348 /* First parameter must be a dict */
2349 item=list_elem(args,0);
2350 if (!item || item->type!=t_dict)
2351 cfgfatal(loc,"site","parameter must be a dictionary\n");
2353 dict=item->data.dict;
2354 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2355 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2357 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2359 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2361 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2363 /* Sanity check (which also allows the 'sites' file to include
2364 site() closures for all sites including our own): refuse to
2365 talk to ourselves */
2366 if (strcmp(st->localname,st->remotename)==0) {
2367 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2369 if (st->peer_mobile != st->local_mobile)
2370 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2371 " but our local-mobile=%d\n",
2372 st->localname, st->peer_mobile, st->local_mobile);
2376 if (st->peer_mobile && st->local_mobile) {
2377 Message(M_WARNING,"site %s: site is mobile but so are we"
2378 " -> ignoring this site\n", st->remotename);
2383 assert(index_sequence < 0xffffffffUL);
2384 st->index = ++index_sequence;
2385 st->local_capabilities = 0;
2386 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2387 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2389 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2390 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2391 if (!things##_cfg) \
2392 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2393 st->nthings=list_length(things##_cfg); \
2394 NEW_ARY(st->things,st->nthings); \
2395 assert(st->nthings); \
2396 for (i=0; i<st->nthings; i++) { \
2397 item_t *item=list_elem(things##_cfg,i); \
2398 if (item->type!=t_closure) \
2399 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2400 closure_t *cl=item->data.closure; \
2401 if (cl->type!=CL_TYPE) \
2402 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2403 st->things[i]=cl->interface; \
2407 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2409 NEW_ARY(st->commclientinfos, st->ncomms);
2410 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2411 for (i=0; i<st->ncomms; i++) {
2412 st->commclientinfos[i] =
2414 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2417 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2418 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2419 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2421 st->defhash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2423 st->privkeys=find_cl_if(dict,"key-cache",CL_PRIVCACHE,False,"site",loc);
2424 if (!st->privkeys) {
2426 find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2427 SETUP_SETHASH(st->privkey_fixed);
2430 struct sigpubkey_if *fixed_pubkey
2431 =find_cl_if(dict,"key",CL_SIGPUBKEY,False,"site",loc);
2432 st->peerkeys_path=dict_read_string(dict,"peer-keys",fixed_pubkey==0,
2434 if (st->peerkeys_path) {
2435 pathprefix_template_init(&st->peerkeys_tmpl,st->peerkeys_path,
2436 PEERKEYS_SUFFIX_MAXLEN + 1 /* nul */);
2437 st->peerkeys_current=keyset_load(st->peerkeys_path,
2438 &st->scratch,st->log,M_ERR,
2441 fixed_pubkey->dispose(fixed_pubkey->st);
2444 assert(fixed_pubkey);
2445 SETUP_SETHASH(fixed_pubkey);
2446 NEW(st->peerkeys_current);
2447 st->peerkeys_current->refcount=1;
2448 st->peerkeys_current->nkeys=1;
2449 st->peerkeys_current->keys[0].id=keyid_zero;
2450 st->peerkeys_current->keys[0].pubkey=fixed_pubkey;
2451 slog(st,LOG_SIGKEYS,
2452 "using old-style fixed peer public key (no `peer-keys')");
2455 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2457 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2458 else st->remoteport=0;
2460 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2462 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2464 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2465 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2466 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2468 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2469 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2470 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2471 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2472 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2474 st->mobile_peer_expiry= dict_read_number(
2475 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2477 const char *peerskey= st->peer_mobile
2478 ? "mobile-peers-max" : "static-peers-max";
2479 st->transport_peers_max= dict_read_number(
2480 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2481 if (st->transport_peers_max<1 ||
2482 st->transport_peers_max>MAX_PEER_ADDRS) {
2483 cfgfatal(loc,"site", "%s must be in range 1.."
2484 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2487 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2488 st->key_renegotiate_time=st->key_lifetime/2;
2490 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2491 st->key_renegotiate_time=dict_read_number(
2492 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2493 if (st->key_renegotiate_time > st->key_lifetime) {
2494 cfgfatal(loc,"site",
2495 "renegotiate-time must be less than key-lifetime\n");
2498 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2499 log_event_table,"site");
2501 st->resolving_count=0;
2502 st->allow_send_prod=0;
2504 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2506 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2508 /* The information we expect to see in incoming messages of type 1 */
2509 /* fixme: lots of unchecked overflows here, but the results are only
2510 corrupted packets rather than undefined behaviour */
2511 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2513 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2515 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2516 BUF_ALLOC(&st->scratch,"site:scratch");
2518 /* We are interested in poll(), but only for timeouts. We don't have
2519 any fds of our own. */
2520 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2523 st->remote_capabilities=0;
2524 st->chosen_transform=0;
2525 st->current.key_timeout=0;
2526 st->auxiliary_key.key_timeout=0;
2527 transport_peers_clear(st,&st->peers);
2528 transport_peers_clear(st,&st->setup_peers);
2529 /* XXX mlock these */
2530 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2531 st->sharedsecretlen=st->sharedsecretallocd=0;
2534 #define SET_CAPBIT(bit) do { \
2535 uint32_t capflag = 1UL << (bit); \
2536 if (st->local_capabilities & capflag) \
2537 slog(st,LOG_ERROR,"capability bit" \
2538 " %d (%#"PRIx32") reused", (bit), capflag); \
2539 st->local_capabilities |= capflag; \
2542 for (i=0; i<st->ntransforms; i++)
2543 SET_CAPBIT(st->transforms[i]->capab_bit);
2547 if (st->local_mobile || st->peer_mobile)
2548 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2550 /* We need to register the remote networks with the netlink device */
2551 uint32_t netlink_mtu; /* local virtual interface mtu */
2552 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2553 if (!st->mtu_target)
2554 st->mtu_target=netlink_mtu;
2556 for (i=0; i<st->ncomms; i++)
2557 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2559 st->current.transform=0;
2560 st->auxiliary_key.transform=0;
2561 st->new_transform=0;
2562 st->auxiliary_is_new=0;
2564 enter_state_stop(st);
2566 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2567 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2569 return new_closure(&st->cl);
2572 void site_module(dict_t *dict)
2574 add_closure(dict,"site",site_apply);
2578 /***** TRANSPORT PEERS definitions *****/
2580 static void transport_peers_debug(struct site *st, transport_peers *dst,
2581 const char *didwhat,
2582 int nargs, const struct comm_addr *args,
2587 if (!(st->log_events & LOG_PEER_ADDRS))
2588 return; /* an optimisation */
2590 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2591 (dst==&st->peers ? "data" :
2592 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2593 didwhat, nargs, dst->npeers);
2595 for (i=0, argp=(void*)args;
2597 i++, (argp+=stride?stride:sizeof(*args))) {
2598 const struct comm_addr *ca=(void*)argp;
2599 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2600 i, comm_addr_to_string(ca));
2602 for (i=0; i<dst->npeers; i++) {
2603 struct timeval diff;
2604 timersub(tv_now,&dst->peers[i].last,&diff);
2605 const struct comm_addr *ca=&dst->peers[i].addr;
2606 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2607 i, comm_addr_to_string(ca),
2608 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2612 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2613 /* peers must be sorted first */
2614 int previous_peers=peers->npeers;
2615 struct timeval oldest;
2616 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2617 oldest.tv_usec = tv_now->tv_usec;
2618 while (peers->npeers>1 &&
2619 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2621 if (peers->npeers != previous_peers)
2622 transport_peers_debug(st,peers,"expire", 0,0,0);
2625 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2626 const struct comm_addr *ca,
2627 const struct timeval *tv) {
2628 /* returns false if output is full */
2631 if (peers->npeers >= st->transport_peers_max)
2634 for (search=0; search<peers->npeers; search++)
2635 if (comm_addr_equal(&peers->peers[search].addr, ca))
2638 peers->peers[peers->npeers].addr = *ca;
2639 peers->peers[peers->npeers].last = *tv;
2644 static void transport_record_peers(struct site *st, transport_peers *peers,
2645 const struct comm_addr *addrs, int naddrs,
2647 /* We add addrs into peers. The new entries end up at the front
2648 * and displace entries towards the end (perhaps even off the
2649 * end). Any existing matching entries are moved up to the front.
2651 * Caller must first call transport_peers_expire. */
2654 /* avoids debug for uninteresting updates */
2656 for (i=0; i<peers->npeers; i++) {
2657 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2658 memmove(peers->peers+1, peers->peers,
2659 sizeof(peers->peers[0]) * i);
2660 peers->peers[0].addr = addrs[0];
2661 peers->peers[0].last = *tv_now;
2667 int old_npeers=peers->npeers;
2668 transport_peer old_peers[old_npeers];
2669 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2673 for (i=0; i<naddrs; i++) {
2674 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2677 for (i=0; i<old_npeers; i++) {
2678 const transport_peer *old=&old_peers[i];
2679 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2683 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2686 static void transport_expire_record_peers(struct site *st,
2687 transport_peers *peers,
2688 const struct comm_addr *addrs,
2689 int naddrs, const char *m) {
2690 /* Convenience function */
2691 transport_peers_expire(st,peers);
2692 transport_record_peers(st,peers,addrs,naddrs,m);
2695 static bool_t transport_compute_setupinit_peers(struct site *st,
2696 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2697 int n_configured_addrs /* 0 if none or not found */,
2698 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2699 if (!n_configured_addrs && !incoming_packet_addr &&
2700 !transport_peers_valid(&st->peers))
2703 slog(st,LOG_SETUP_INIT,
2704 "using: %d configured addr(s);%s %d old peer addrs(es)",
2706 incoming_packet_addr ? " incoming packet address;" : "",
2709 /* Non-mobile peers try addresses until one is plausible. The
2710 * effect is that this code always tries first the configured
2711 * address if supplied, or otherwise the address of the incoming
2712 * PROD, or finally the existing data peer if one exists; this is
2715 transport_peers_copy(st,&st->setup_peers,&st->peers);
2716 transport_peers_expire(st,&st->setup_peers);
2718 if (incoming_packet_addr)
2719 transport_record_peers(st,&st->setup_peers,
2720 incoming_packet_addr,1, "incoming");
2722 if (n_configured_addrs)
2723 transport_record_peers(st,&st->setup_peers,
2724 configured_addrs,n_configured_addrs, "setupinit");
2726 assert(transport_peers_valid(&st->setup_peers));
2730 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2731 if (st->peer_mobile)
2732 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2734 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2735 if (st->peer_mobile)
2736 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2739 static int transport_peers_valid(transport_peers *peers) {
2740 return peers->npeers;
2742 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2744 transport_peers_debug(st,peers,"clear",0,0,0);
2746 static void transport_peers_copy(struct site *st, transport_peers *dst,
2747 const transport_peers *src) {
2748 dst->npeers=src->npeers;
2749 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2750 transport_peers_debug(st,dst,"copy",
2751 src->npeers, &src->peers->addr, sizeof(*src->peers));
2754 static void transport_resolve_complete(struct site *st,
2755 const struct comm_addr *addrs,
2757 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2759 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2763 static void transport_resolve_complete_tardy(struct site *st,
2764 const struct comm_addr *addrs,
2766 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2767 "resolved tardily");
2770 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2772 const transport_peers *inp) {
2773 /* out and in->peers may be the same region, or nonoverlapping */
2774 const transport_peer *in=inp->peers;
2776 for (slot=0; slot<inp->npeers; slot++) {
2777 if (!(mask & (1U << slot)))
2779 if (!(out==in && slot==*nout_io))
2780 COPY_OBJ(out[*nout_io], in[slot]);
2785 void transport_xmit(struct site *st, transport_peers *peers,
2786 struct buffer_if *buf, bool_t candebug) {
2788 transport_peers_expire(st, peers);
2789 unsigned failed=0; /* bitmask */
2790 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2793 for (slot=0; slot<peers->npeers; slot++) {
2794 transport_peer *peer=&peers->peers[slot];
2795 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2797 dump_packet(st, buf, &peer->addr, False, ok);
2799 failed |= 1U << slot;
2802 if (ok && !st->peer_mobile)
2805 /* Now we need to demote/delete failing addrs: if we are mobile we
2806 * merely demote them; otherwise we delete them. */
2807 if (st->local_mobile) {
2808 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2809 /* `expected' has all the failures at the end already */
2810 if (failed != expected) {
2812 transport_peer failedpeers[nfailed];
2813 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2814 assert(fslot == nfailed);
2816 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2817 assert(wslot+nfailed == peers->npeers);
2818 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2819 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2822 if (failed && peers->npeers > 1) {
2824 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2825 peers->npeers=wslot;
2826 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2831 /***** END of transport peers declarations *****/