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 random_if *random;
322 struct privcache_if *privkeys;
323 struct sigprivkey_if *privkey_fixed;
324 struct transform_if **transforms;
328 uint32_t index; /* Index of this site */
329 uint32_t early_capabilities;
330 uint32_t local_capabilities;
331 int32_t setup_retries; /* How many times to send setup packets */
332 int32_t setup_retry_interval; /* Initial timeout for setup packets */
333 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
334 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
335 int32_t key_lifetime; /* How long a key lasts once set up */
336 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
337 after this time, initiate a new
340 bool_t our_name_later; /* our name > peer name */
343 /* runtime information */
345 uint64_t now; /* Most recently seen time */
346 bool_t allow_send_prod;
347 bool_t msg1_crossed_logged;
349 int resolving_n_results_all;
350 int resolving_n_results_stored;
351 struct comm_addr resolving_results[MAX_PEER_ADDRS];
352 const char *peerkeys_path;
353 struct pathprefix_template peerkeys_tmpl;
354 struct peer_keyset *peerkeys_current, *peerkeys_kex;
356 /* The currently established session */
357 struct data_key current;
358 struct data_key auxiliary_key;
359 bool_t auxiliary_is_new;
360 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
361 uint64_t auxiliary_renegotiate_key_time;
362 transport_peers peers; /* Current address(es) of peer for data traffic */
364 /* The current key setup protocol exchange. We can only be
365 involved in one of these at a time. There's a potential for
366 denial of service here (the attacker keeps sending a setup
367 packet; we keep trying to continue the exchange, and have to
368 timeout before we can listen for another setup packet); perhaps
369 we should keep a list of 'bad' sources for setup packets. */
370 uint32_t remote_capabilities;
371 uint16_t remote_adv_mtu;
372 struct transform_if *chosen_transform;
373 uint32_t setup_session_id;
374 transport_peers setup_peers;
375 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
376 uint8_t remoteN[NONCELEN];
377 struct buffer_if buffer; /* Current outgoing key exchange packet */
378 struct buffer_if scratch;
379 int32_t retries; /* Number of retries remaining */
380 uint64_t timeout; /* Timeout for current state */
382 uint8_t *sharedsecret;
383 uint32_t sharedsecretlen, sharedsecretallocd;
384 struct transform_inst_if *new_transform; /* For key setup/verify */
387 static uint32_t event_log_priority(struct site *st, uint32_t event)
389 if (!(event&st->log_events))
392 case LOG_UNEXPECTED: return M_INFO;
393 case LOG_SETUP_INIT: return M_INFO;
394 case LOG_SETUP_TIMEOUT: return M_NOTICE;
395 case LOG_ACTIVATE_KEY: return M_INFO;
396 case LOG_TIMEOUT_KEY: return M_INFO;
397 case LOG_SEC: return M_SECURITY;
398 case LOG_STATE: return M_DEBUG;
399 case LOG_DROP: return M_DEBUG;
400 case LOG_DUMP: return M_DEBUG;
401 case LOG_ERROR: return M_ERR;
402 case LOG_PEER_ADDRS: return M_DEBUG;
403 case LOG_SIGKEYS: return M_INFO;
404 default: return M_ERR;
408 static uint32_t slog_start(struct site *st, uint32_t event)
410 uint32_t class=event_log_priority(st, event);
412 slilog_part(st->log,class,"%s: ",st->tunname);
417 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
419 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
423 class=slog_start(st,event);
425 vslilog_part(st->log,class,msg,ap);
426 slilog_part(st->log,class,"\n");
430 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
432 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
436 vslog(st,event,msg,ap);
440 static void logtimeout(struct site *st, const char *fmt, ...)
442 static void logtimeout(struct site *st, const char *fmt, ...)
444 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
451 slilog_part(st->log,class,"%s: ",st->tunname);
452 vslilog_part(st->log,class,fmt,ap);
456 for (i=0, delim=" (tried ";
457 i<st->setup_peers.npeers;
459 transport_peer *peer=&st->setup_peers.peers[i];
460 const char *s=comm_addr_to_string(&peer->addr);
461 slilog_part(st->log,class,"%s%s",delim,s);
464 slilog_part(st->log,class,")\n");
468 static void set_link_quality(struct site *st);
469 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
470 static void delete_one_key(struct site *st, struct data_key *key,
471 const char *reason /* may be 0 meaning don't log*/,
472 const char *which /* ignored if !reasonn */,
473 uint32_t loglevel /* ignored if !reasonn */);
474 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
475 const struct comm_addr *prod_hint);
476 static void enter_state_run(struct site *st);
477 static bool_t enter_state_resolve(struct site *st);
478 static void decrement_resolving_count(struct site *st, int by);
479 static bool_t enter_new_state(struct site *st,uint32_t next,
480 const struct msg *prompt
481 /* may be 0 for SENTMSG1 */);
482 static void enter_state_wait(struct site *st);
483 static void activate_new_key(struct site *st);
485 static bool_t is_transform_valid(struct transform_inst_if *transform)
487 return transform && transform->valid(transform->st);
490 static bool_t current_valid(struct site *st)
492 return is_transform_valid(st->current.transform);
495 #define DEFINE_CALL_TRANSFORM(fwdrev) \
496 static transform_apply_return \
497 call_transform_##fwdrev(struct site *st, \
498 struct transform_inst_if *transform, \
499 struct buffer_if *buf, \
500 const char **errmsg) \
502 if (!is_transform_valid(transform)) { \
503 *errmsg="transform not set up"; \
504 return transform_apply_err; \
506 return transform->fwdrev(transform->st,buf,errmsg); \
509 DEFINE_CALL_TRANSFORM(forwards)
510 DEFINE_CALL_TRANSFORM(reverse)
512 static void dispose_transform(struct transform_inst_if **transform_var)
514 struct transform_inst_if *transform=*transform_var;
516 transform->delkey(transform->st);
517 transform->destroy(transform->st);
522 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
523 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
524 #define CHECK_TYPE(b,t) do { uint32_t type; \
525 CHECK_AVAIL((b),4); \
526 type=buf_unprepend_uint32((b)); \
527 if (type!=(t)) return False; } while(0)
529 static _Bool type_is_msg23(uint32_t type)
532 case LABEL_MSG2: case CASES_MSG3_KNOWN: return True;
533 default: return False;
536 static _Bool type_is_msg34(uint32_t type)
539 case CASES_MSG3_KNOWN: case LABEL_MSG4: return True;
540 default: return False;
547 struct buffer_if extrainfo;
554 struct parsedname remote;
555 struct parsedname local;
556 uint32_t remote_capabilities;
558 int capab_transformnum;
564 struct alg_msg_data sig;
565 int n_pubkeys_accepted_nom; /* may be > MAX_SIG_KEYS ! */
566 const struct sigkeyid *pubkeys_accepted[MAX_SIG_KEYS];
567 int signing_key_index;
570 static const struct sigkeyid keyid_zero;
572 static int32_t wait_timeout(struct site *st) {
573 int32_t t = st->wait_timeout_mean;
576 st->random->generate(st->random->st,sizeof(factor),&factor);
577 t += (t / 256) * factor;
582 static _Bool set_new_transform(struct site *st, char *pk)
586 /* Make room for the shared key */
587 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
588 assert(st->sharedsecretlen);
589 if (st->sharedsecretlen > st->sharedsecretallocd) {
590 st->sharedsecretallocd=st->sharedsecretlen;
591 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
592 st->sharedsecretallocd,
593 "site:sharedsecret");
596 /* Generate the shared key */
597 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
598 st->sharedsecret,st->sharedsecretlen);
600 /* Set up the transform */
601 struct transform_if *generator=st->chosen_transform;
602 struct transform_inst_if *generated=generator->create(generator->st);
603 ok = generated->setkey(generated->st,st->sharedsecret,
604 st->sharedsecretlen,st->our_name_later);
606 dispose_transform(&st->new_transform);
607 if (!ok) return False;
608 st->new_transform=generated;
610 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
611 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
612 st->chosen_transform->capab_bit,
613 st->local_capabilities, st->remote_capabilities);
618 int32_t lenpos, afternul;
620 static void append_string_xinfo_start(struct buffer_if *buf,
621 struct xinfoadd *xia,
623 /* Helps construct one of the names with additional info as found
624 * in MSG1..4. Call this function first, then append all the
625 * desired extra info (not including the nul byte) to the buffer,
626 * then call append_string_xinfo_done. */
628 xia->lenpos = buf->size;
629 buf_append_string(buf,str);
630 buf_append_uint8(buf,0);
631 xia->afternul = buf->size;
633 static void append_string_xinfo_done(struct buffer_if *buf,
634 struct xinfoadd *xia)
636 /* we just need to adjust the string length */
637 if (buf->size == xia->afternul) {
638 /* no extra info, strip the nul too */
639 buf_unappend_uint8(buf);
641 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
645 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
646 out using a transform of config data supplied by netlink */
647 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what,
648 const struct msg *prompt
649 /* may be 0 for MSG1 */)
655 st->retries=st->setup_retries;
656 BUF_ALLOC(&st->buffer,what);
657 buffer_init(&st->buffer,0);
658 buf_append_uint32(&st->buffer,
659 (type==LABEL_MSG1?0:st->setup_session_id));
660 buf_append_uint32(&st->buffer,st->index);
661 buf_append_uint32(&st->buffer,type);
664 append_string_xinfo_start(&st->buffer,&xia,st->localname);
665 if ((st->local_capabilities & st->early_capabilities) ||
666 (type != LABEL_MSG1)) {
667 buf_append_uint32(&st->buffer,st->local_capabilities);
669 if (type_is_msg34(type)) {
670 buf_append_uint16(&st->buffer,st->mtu_target);
672 if (type_is_msg23(type)) {
673 buf_append_uint8(&st->buffer,st->peerkeys_kex->nkeys);
674 for (ki=0; ki<st->peerkeys_kex->nkeys; ki++) {
675 struct peer_pubkey *pk = &st->peerkeys_kex->keys[ki];
676 BUF_ADD_OBJ(append,&st->buffer,pk->id);
679 struct sigprivkey_if *privkey=0;
680 if (type_is_msg34(type)) {
681 assert(prompt->n_pubkeys_accepted_nom>0);
683 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
685 const struct sigkeyid *kid=prompt->pubkeys_accepted[ki];
687 privkey=st->privkeys->lookup(st->privkeys->st,kid,st->log);
688 if (privkey) goto privkey_found;
690 if (sigkeyid_equal(&keyid_zero,kid)) {
691 privkey=st->privkey_fixed;
696 uint32_t class = slog_start(st,LOG_ERROR);
698 slilog_part(st->log,class,"no suitable private key, peer wanted");
700 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
702 slilog_part(st->log,class, " " SIGKEYID_PR_FMT,
703 SIGKEYID_PR_VAL(prompt->pubkeys_accepted[ki]));
705 if (prompt->n_pubkeys_accepted_nom > MAX_SIG_KEYS)
706 slilog_part(st->log,class," +%d",
707 prompt->n_pubkeys_accepted_nom - MAX_SIG_KEYS);
708 slilog_part(st->log,class,"\n");
713 buf_append_uint8(&st->buffer,ki);
716 append_string_xinfo_done(&st->buffer,&xia);
718 buf_append_string(&st->buffer,st->remotename);
719 BUF_ADD_OBJ(append,&st->buffer,st->localN);
720 if (type==LABEL_MSG1) return True;
721 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
722 if (type==LABEL_MSG2) return True;
724 if (hacky_par_mid_failnow()) return False;
726 if (MSGMAJOR(type) == 3) do {
727 minor = MSGMINOR(type);
728 if (minor < 1) break;
729 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
732 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
733 buf_append_string(&st->buffer,dhpub);
736 bool_t ok=privkey->sign(privkey->st,
747 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
750 nm->len=buf_unprepend_uint16(msg);
751 CHECK_AVAIL(msg,nm->len);
752 nm->name=buf_unprepend(msg,nm->len);
753 uint8_t *nul=memchr(nm->name,0,nm->len);
755 buffer_readonly_view(&nm->extrainfo,0,0);
757 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
758 nm->len=nul-nm->name;
763 static bool_t unpick_msg(struct site *st, uint32_t type,
764 struct buffer_if *msg, struct msg *m)
768 m->n_pubkeys_accepted_nom=-1;
769 m->capab_transformnum=-1;
770 m->signing_key_index=-1;
771 m->hashstart=msg->start;
773 m->dest=buf_unprepend_uint32(msg);
775 m->source=buf_unprepend_uint32(msg);
776 CHECK_TYPE(msg,type);
777 if (!unpick_name(msg,&m->remote)) return False;
778 m->remote_capabilities=0;
780 if (m->remote.extrainfo.size) {
781 CHECK_AVAIL(&m->remote.extrainfo,4);
782 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
784 if (type_is_msg34(type) && m->remote.extrainfo.size) {
785 CHECK_AVAIL(&m->remote.extrainfo,2);
786 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
788 if (type_is_msg23(type) && m->remote.extrainfo.size) {
789 m->n_pubkeys_accepted_nom = buf_unprepend_uint8(&m->remote.extrainfo);
790 if (!m->n_pubkeys_accepted_nom) return False;
791 for (int ki_nom=0; ki_nom<m->n_pubkeys_accepted_nom; ki_nom++) {
792 CHECK_AVAIL(&m->remote.extrainfo,KEYIDSZ);
793 struct sigkeyid *kid = buf_unprepend(&m->remote.extrainfo,KEYIDSZ);
794 if (ki_nom<MAX_SIG_KEYS) m->pubkeys_accepted[ki_nom] = kid;
797 m->n_pubkeys_accepted_nom = 1;
798 m->pubkeys_accepted[0] = &keyid_zero;
800 if (type_is_msg34(type) && m->remote.extrainfo.size) {
801 m->signing_key_index=buf_unprepend_uint8(&m->remote.extrainfo);
803 m->signing_key_index=0;
805 if (!unpick_name(msg,&m->local)) return False;
806 if (type==LABEL_PROD) {
810 CHECK_AVAIL(msg,NONCELEN);
811 m->nR=buf_unprepend(msg,NONCELEN);
812 if (type==LABEL_MSG1) {
816 CHECK_AVAIL(msg,NONCELEN);
817 m->nL=buf_unprepend(msg,NONCELEN);
818 if (type==LABEL_MSG2) {
822 if (MSGMAJOR(type) == 3) do {
823 minor = MSGMINOR(type);
824 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
825 if (minor < (minminor)) \
826 m->capab_##kind##num = (dflt); \
828 CHECK_AVAIL(msg, 1); \
829 m->capab_##kind##num = buf_unprepend_uint8(msg); \
832 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
833 #undef MAYBE_READ_CAP
836 m->pklen=buf_unprepend_uint16(msg);
837 CHECK_AVAIL(msg,m->pklen);
838 m->pk=buf_unprepend(msg,m->pklen);
839 m->hashlen=msg->start-m->hashstart;
841 if (m->signing_key_index < 0 ||
842 m->signing_key_index >= st->peerkeys_kex->nkeys) {
845 struct sigpubkey_if *pubkey=
846 st->peerkeys_kex->keys[m->signing_key_index].pubkey;
847 if (!pubkey->unpick(pubkey->st,msg,&m->sig)) {
856 static bool_t name_matches(const struct parsedname *nm, const char *expected)
858 int expected_len=strlen(expected);
860 nm->len == expected_len &&
861 !memcmp(nm->name, expected, expected_len);
864 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
867 if (type==LABEL_MSG1) return True;
869 /* Check that the site names and our nonce have been sent
870 back correctly, and then store our peer's nonce. */
871 if (!name_matches(&m->remote,st->remotename)) {
872 *error="wrong remote site name";
875 if (!name_matches(&m->local,st->localname)) {
876 *error="wrong local site name";
879 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
880 *error="wrong locally-generated nonce";
883 if (type==LABEL_MSG2) return True;
884 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
885 *error="wrong remotely-generated nonce";
888 /* MSG3 has complicated rules about capabilities, which are
889 * handled in process_msg3. */
890 if (MSGMAJOR(type) == 3) return True;
891 if (m->remote_capabilities!=st->remote_capabilities) {
892 *error="remote capabilities changed";
895 if (type==LABEL_MSG4) return True;
896 *error="unknown message type";
900 static void peerkeys_maybe_incorporate(struct site *st, const char *file,
901 const char *whatmore,
904 struct peer_keyset *atsuffix=
905 keyset_load(file,&st->scratch,st->log,logcl_enoent);
906 if (!atsuffix) return;
908 if (st->peerkeys_current &&
909 serial_cmp(atsuffix->serial,st->peerkeys_current->serial) <= 0) {
910 slog(st,LOG_SIGKEYS,"keys from %s%s are older, discarding",
912 keyset_dispose(&atsuffix);
914 if (r) slog(st,LOG_ERROR,"failed to remove old key update %s: %s\n",
915 st->peerkeys_tmpl.buffer,strerror(errno));
918 slog(st,LOG_SIGKEYS,"keys from %s%s are newer, installing",
920 keyset_dispose(&st->peerkeys_current);
921 st->peerkeys_current=atsuffix;
922 int r=rename(file,st->peerkeys_path);
923 if (r) slog(st,LOG_ERROR,"failed to install key update %s as %s: %s\n",
924 st->peerkeys_tmpl.buffer,st->peerkeys_path,
929 static void peerkeys_check_for_update(struct site *st)
933 * <F> live file, loaded on startup, updated by secnet
934 * (only). * in-memory peerkeys_current is kept
935 * synced with this file
937 * <F>~update update file from config manager, checked before
938 * every key exchange. config manager must rename
939 * this file into place; it will be renamed and
940 * then removed by secnet.
942 * <F>~proc update file being processed by secnet.
943 * only secnet may write or remove.
945 * <F>~incoming update file from peer, being received by secnet
946 * may be incomplete, unverified, or even malicious
947 * only secnet may write or remove.
949 if (!st->peerkeys_path) return;
951 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~proc");
952 peerkeys_maybe_incorporate(st,st->peerkeys_tmpl.buffer,
953 " (found old update)",
956 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~update");
957 const char *inputp=st->peerkeys_tmpl.buffer;
958 if (access(inputp,R_OK)) {
960 slog(st,LOG_ERROR,"cannot access peer key update file %s\n",
965 buffer_init(&st->scratch,0);
966 BUF_ADD_BYTES(append,&st->scratch,
967 st->peerkeys_tmpl.buffer,
968 strlen(st->peerkeys_tmpl.buffer)+1);
969 inputp=st->scratch.start;
971 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~proc");
972 const char *oursp=st->peerkeys_tmpl.buffer;
974 int r=rename(inputp,oursp);
976 slog(st,LOG_ERROR,"failed to claim key update file %s as %s: %s\n",
977 inputp,oursp,strerror(errno));
981 peerkeys_maybe_incorporate(st,oursp," (update)",M_ERR);
985 static bool_t kex_init(struct site *st)
987 keyset_dispose(&st->peerkeys_kex);
988 peerkeys_check_for_update(st);
989 if (!st->peerkeys_current) {
990 slog(st,LOG_SETUP_INIT,"no peer public keys, abandoning key setup");
993 st->peerkeys_kex = keyset_dup(st->peerkeys_current);
994 st->random->generate(st->random->st,NONCELEN,st->localN);
998 static bool_t generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
1001 generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
1004 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
1005 const struct comm_addr *src,
1006 const struct msg *m)
1008 /* We've already determined we're in an appropriate state to
1009 process an incoming MSG1, and that the MSG1 has correct values
1012 st->setup_session_id=m->source;
1013 st->remote_capabilities=m->remote_capabilities;
1014 memcpy(st->remoteN,m->nR,NONCELEN);
1018 static bool_t generate_msg2(struct site *st,
1019 const struct msg *prompt_may_be_null)
1022 generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
1025 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
1026 const struct comm_addr *src,
1027 struct msg *m /* returned */)
1031 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
1032 if (!check_msg(st,LABEL_MSG2,m,&err)) {
1033 slog(st,LOG_SEC,"msg2: %s",err);
1036 st->setup_session_id=m->source;
1037 st->remote_capabilities=m->remote_capabilities;
1039 /* Select the transform to use */
1041 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
1042 if (!remote_crypto_caps)
1043 /* old secnets only had this one transform */
1044 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
1046 #define CHOOSE_CRYPTO(kind, whats) do { \
1047 struct kind##_if *iface; \
1048 uint32_t bit, ours = 0; \
1050 for (i= 0; i < st->n##kind##s; i++) { \
1051 iface=st->kind##s[i]; \
1052 bit = 1UL << iface->capab_bit; \
1053 if (bit & remote_crypto_caps) goto kind##_found; \
1056 slog(st,LOG_ERROR,"no " whats " in common" \
1057 " (us %#"PRIx32"; them: %#"PRIx32")", \
1058 st->local_capabilities & ours, remote_crypto_caps); \
1061 st->chosen_##kind = iface; \
1064 CHOOSE_CRYPTO(transform, "transforms");
1066 #undef CHOOSE_CRYPTO
1068 memcpy(st->remoteN,m->nR,NONCELEN);
1072 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
1074 /* Now we have our nonce and their nonce. Think of a secret key,
1075 and create message number 3. */
1076 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1077 return generate_msg(st,
1078 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
1081 "site:MSG3",prompt);
1084 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
1086 /* Check signature and store g^x mod m */
1089 if (m->signing_key_index >= 0) {
1090 if (m->signing_key_index >= st->peerkeys_kex->nkeys)
1092 ki=m->signing_key_index;
1094 for (ki=0; ki<st->peerkeys_kex->nkeys; ki++)
1095 if (sigkeyid_equal(&keyid_zero,&st->peerkeys_kex->keys[ki].id))
1099 "peer signed with keyid zero, which we do not accept");
1103 struct sigpubkey_if *pubkey=st->peerkeys_kex->keys[ki].pubkey;
1105 if (!pubkey->check(pubkey->st,
1106 m->hashstart,m->hashlen,
1108 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
1112 st->remote_adv_mtu=m->remote_mtu;
1117 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
1118 const struct comm_addr *src, uint32_t msgtype,
1119 struct msg *m /* returned */)
1124 case CASES_MSG3_KNOWN: break;
1128 if (!unpick_msg(st,msgtype,msg3,m)) return False;
1129 if (!check_msg(st,msgtype,m,&err)) {
1130 slog(st,LOG_SEC,"msg3: %s",err);
1133 uint32_t capab_adv_late = m->remote_capabilities
1134 & ~st->remote_capabilities & st->early_capabilities;
1135 if (capab_adv_late) {
1136 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
1137 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
1138 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
1142 #define CHOSE_CRYPTO(kind, what) do { \
1143 struct kind##_if *iface; \
1145 for (i=0; i<st->n##kind##s; i++) { \
1146 iface=st->kind##s[i]; \
1147 if (iface->capab_bit == m->capab_##kind##num) \
1148 goto kind##_found; \
1150 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
1151 m->capab_##kind##num); \
1154 st->chosen_##kind=iface; \
1157 CHOSE_CRYPTO(transform, "transform");
1161 if (!process_msg3_msg4(st,m))
1164 /* Update our idea of the remote site's capabilities, now that we've
1165 * verified that its message was authentic.
1167 * Our previous idea of the remote site's capabilities came from the
1168 * unauthenticated MSG1. We've already checked that this new message
1169 * doesn't change any of the bits we relied upon in the past, but it may
1170 * also have set additional capability bits. We simply throw those away
1171 * now, and use the authentic capabilities from this MSG3. */
1172 st->remote_capabilities=m->remote_capabilities;
1174 /* Terminate their DH public key with a '0' */
1176 /* Invent our DH secret key */
1177 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1179 /* Generate the shared key and set up the transform */
1180 if (!set_new_transform(st,m->pk)) return False;
1185 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
1187 /* We have both nonces, their public key and our private key. Generate
1188 our public key, sign it and send it to them. */
1189 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
1192 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
1193 const struct comm_addr *src,
1194 struct msg *m /* returned */)
1198 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
1199 if (!check_msg(st,LABEL_MSG4,m,&err)) {
1200 slog(st,LOG_SEC,"msg4: %s",err);
1204 if (!process_msg3_msg4(st,m))
1207 /* Terminate their DH public key with a '0' */
1210 /* Generate the shared key and set up the transform */
1211 if (!set_new_transform(st,m->pk)) return False;
1222 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1225 CHECK_AVAIL(msg0,4);
1226 m->dest=buf_unprepend_uint32(msg0);
1227 CHECK_AVAIL(msg0,4);
1228 m->source=buf_unprepend_uint32(msg0);
1229 CHECK_AVAIL(msg0,4);
1230 m->type=buf_unprepend_uint32(msg0);
1232 /* Leaves transformed part of buffer untouched */
1235 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1237 cstring_t transform_err;
1239 BUF_ALLOC(&st->buffer,"site:MSG5");
1240 /* We are going to add four words to the message */
1241 buffer_init(&st->buffer,calculate_max_start_pad());
1242 /* Give the netlink code an opportunity to put its own stuff in the
1243 message (configuration information, etc.) */
1244 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1245 if (call_transform_forwards(st,st->new_transform,
1246 &st->buffer,&transform_err))
1248 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1249 buf_prepend_uint32(&st->buffer,st->index);
1250 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1252 st->retries=st->setup_retries;
1256 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1257 const struct comm_addr *src,
1258 struct transform_inst_if *transform)
1261 cstring_t transform_err;
1263 if (!unpick_msg0(st,msg5,&m)) return False;
1265 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1266 /* There's a problem */
1267 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1270 /* Buffer should now contain untransformed PING packet data */
1271 CHECK_AVAIL(msg5,4);
1272 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1273 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1276 /* Older versions of secnet used to write some config data here
1277 * which we ignore. So we don't CHECK_EMPTY */
1281 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1282 uint32_t session_id)
1284 cstring_t transform_err;
1286 BUF_ALLOC(&st->buffer,"site:MSG6");
1287 /* We are going to add four words to the message */
1288 buffer_init(&st->buffer,calculate_max_start_pad());
1289 /* Give the netlink code an opportunity to put its own stuff in the
1290 message (configuration information, etc.) */
1291 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1292 transform_apply_return problem =
1293 call_transform_forwards(st,transform,
1294 &st->buffer,&transform_err);
1296 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1297 buf_prepend_uint32(&st->buffer,st->index);
1298 buf_prepend_uint32(&st->buffer,session_id);
1301 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1303 if (!is_transform_valid(st->new_transform))
1305 create_msg6(st,st->new_transform,st->setup_session_id);
1306 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1310 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1311 const struct comm_addr *src)
1314 cstring_t transform_err;
1316 if (!unpick_msg0(st,msg6,&m)) return False;
1318 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1319 /* There's a problem */
1320 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1323 /* Buffer should now contain untransformed PING packet data */
1324 CHECK_AVAIL(msg6,4);
1325 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1326 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1329 /* Older versions of secnet used to write some config data here
1330 * which we ignore. So we don't CHECK_EMPTY */
1334 static transform_apply_return
1335 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1336 const struct comm_addr *src)
1338 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1340 transform_apply_return problem;
1342 if (!unpick_msg0(st,msg0,&m)) return False;
1344 /* Keep a copy so we can try decrypting it with multiple keys */
1345 buffer_copy(&st->scratch, msg0);
1347 problem = call_transform_reverse(st,st->current.transform,
1348 msg0,&transform_err);
1350 if (!st->auxiliary_is_new)
1351 delete_one_key(st,&st->auxiliary_key,
1352 "peer has used new key","auxiliary key",LOG_SEC);
1355 if (transform_apply_return_badseq(problem))
1358 buffer_copy(msg0, &st->scratch);
1359 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1362 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1363 if (st->auxiliary_is_new) {
1364 /* We previously timed out in state SENTMSG5 but it turns
1365 * out that our peer did in fact get our MSG5 and is
1366 * using the new key. So we should switch to it too. */
1367 /* This is a bit like activate_new_key. */
1370 st->current=st->auxiliary_key;
1371 st->auxiliary_key=t;
1373 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1374 "previous key",LOG_SEC);
1375 st->auxiliary_is_new=0;
1376 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1380 if (transform_apply_return_badseq(problem))
1383 if (st->state==SITE_SENTMSG5) {
1384 buffer_copy(msg0, &st->scratch);
1385 problem = call_transform_reverse(st,st->new_transform,
1388 /* It looks like we didn't get the peer's MSG6 */
1389 /* This is like a cut-down enter_new_state(SITE_RUN) */
1390 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1391 BUF_FREE(&st->buffer);
1393 activate_new_key(st);
1394 return 0; /* do process the data in this packet */
1396 if (transform_apply_return_badseq(problem))
1400 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1401 transform_err,auxkey_err,newkey_err);
1402 initiate_key_setup(st,"incoming message would not decrypt",0);
1403 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1408 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1413 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1414 const struct comm_addr *src)
1417 transform_apply_return problem;
1419 problem = decrypt_msg0(st,msg0,src);
1420 if (problem==transform_apply_seqdupe) {
1421 /* We recently received another copy of this packet, maybe due
1422 * to polypath. That's not a problem; indeed, for the
1423 * purposes of transport address management it is a success.
1424 * But we don't want to process the packet. */
1425 transport_data_msgok(st,src);
1431 CHECK_AVAIL(msg0,4);
1432 type=buf_unprepend_uint32(msg0);
1435 /* We must forget about the current session. */
1436 delete_keys(st,"request from peer",LOG_SEC);
1437 /* probably, the peer is shutting down, and this is going to fail,
1438 * but we need to be trying to bring the link up again */
1440 initiate_key_setup(st,"peer requested key teardown",0);
1443 /* Deliver to netlink layer */
1444 st->netlink->deliver(st->netlink->st,msg0);
1445 transport_data_msgok(st,src);
1446 /* See whether we should start negotiating a new key */
1447 if (st->now > st->renegotiate_key_time)
1448 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1451 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1458 static void dump_packet(struct site *st, struct buffer_if *buf,
1459 const struct comm_addr *addr, bool_t incoming,
1462 uint32_t dest=get_uint32(buf->start);
1463 uint32_t source=get_uint32(buf->start+4);
1464 uint32_t msgtype=get_uint32(buf->start+8);
1466 if (st->log_events & LOG_DUMP)
1467 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1468 st->tunname,incoming?"incoming":"outgoing",
1469 dest,source,msgtype,comm_addr_to_string(addr),
1473 static bool_t comm_addr_sendmsg(struct site *st,
1474 const struct comm_addr *dest,
1475 struct buffer_if *buf)
1478 struct comm_clientinfo *commclientinfo = 0;
1480 for (i=0; i < st->ncomms; i++) {
1481 if (st->comms[i] == dest->comm) {
1482 commclientinfo = st->commclientinfos[i];
1486 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1489 static uint32_t site_status(void *st)
1494 static bool_t send_msg(struct site *st)
1496 if (st->retries>0) {
1497 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1498 st->timeout=st->now+st->setup_retry_interval;
1501 } else if (st->state==SITE_SENTMSG5) {
1502 logtimeout(st,"timed out sending MSG5, stashing new key");
1503 /* We stash the key we have produced, in case it turns out that
1504 * our peer did see our MSG5 after all and starts using it. */
1505 /* This is a bit like some of activate_new_key */
1506 struct transform_inst_if *t;
1507 t=st->auxiliary_key.transform;
1508 st->auxiliary_key.transform=st->new_transform;
1509 st->new_transform=t;
1510 dispose_transform(&st->new_transform);
1512 st->auxiliary_is_new=1;
1513 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1514 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1515 st->auxiliary_key.remote_session_id=st->setup_session_id;
1517 enter_state_wait(st);
1520 logtimeout(st,"timed out sending key setup packet "
1521 "(in state %s)",state_name(st->state));
1522 enter_state_wait(st);
1527 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1528 int stored_naddrs, int all_naddrs,
1529 const char *address, const char *failwhy)
1531 struct site *st=sst;
1533 if (!stored_naddrs) {
1534 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1536 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1537 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1539 int space=st->transport_peers_max-st->resolving_n_results_stored;
1540 int n_tocopy=MIN(stored_naddrs,space);
1541 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1544 st->resolving_n_results_stored += n_tocopy;
1545 st->resolving_n_results_all += all_naddrs;
1548 decrement_resolving_count(st,1);
1551 static void decrement_resolving_count(struct site *st, int by)
1553 assert(st->resolving_count>0);
1554 st->resolving_count-=by;
1556 if (st->resolving_count)
1559 /* OK, we are done with them all. Handle combined results. */
1561 const struct comm_addr *addrs=st->resolving_results;
1562 int naddrs=st->resolving_n_results_stored;
1563 assert(naddrs<=st->transport_peers_max);
1566 if (naddrs != st->resolving_n_results_all) {
1567 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1568 " yielded too many results (%d > %d), some ignored",
1569 st->resolving_n_results_all, naddrs);
1571 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1572 naddrs, iaddr_to_string(&addrs[0].ia));;
1575 switch (st->state) {
1577 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1578 enter_new_state(st,SITE_SENTMSG1,0);
1580 /* Can't figure out who to try to to talk to */
1581 slog(st,LOG_SETUP_INIT,
1582 "key exchange failed: cannot find peer address");
1583 enter_state_run(st);
1586 case SITE_SENTMSG1: case SITE_SENTMSG2:
1587 case SITE_SENTMSG3: case SITE_SENTMSG4:
1590 /* We start using the address immediately for data too.
1591 * It's best to store it in st->peers now because we might
1592 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1593 * the new key (without updating the data peer addrs). */
1594 transport_resolve_complete(st,addrs,naddrs);
1595 } else if (st->local_mobile) {
1596 /* We can't let this rest because we may have a peer
1597 * address which will break in the future. */
1598 slog(st,LOG_SETUP_INIT,"resolution failed: "
1599 "abandoning key exchange");
1600 enter_state_wait(st);
1602 slog(st,LOG_SETUP_INIT,"resolution failed: "
1603 " continuing to use source address of peer's packets"
1604 " for key exchange and ultimately data");
1609 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1610 " updating peer address(es)");
1611 transport_resolve_complete_tardy(st,addrs,naddrs);
1612 } else if (st->local_mobile) {
1613 /* Not very good. We should queue (another) renegotiation
1614 * so that we can update the peer address. */
1615 st->key_renegotiate_time=st->now+wait_timeout(st);
1617 slog(st,LOG_SETUP_INIT,"resolution failed: "
1618 " continuing to use source address of peer's packets");
1628 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1629 const struct comm_addr *prod_hint)
1631 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1632 if (st->state!=SITE_RUN) return False;
1633 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1634 if (st->addresses) {
1635 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1636 return enter_state_resolve(st);
1637 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1638 return enter_new_state(st,SITE_SENTMSG1,0);
1640 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1644 static void activate_new_key(struct site *st)
1646 struct transform_inst_if *t;
1648 /* We have three transform instances, which we swap between old,
1650 t=st->auxiliary_key.transform;
1651 st->auxiliary_key.transform=st->current.transform;
1652 st->current.transform=st->new_transform;
1653 st->new_transform=t;
1654 dispose_transform(&st->new_transform);
1657 st->auxiliary_is_new=0;
1658 st->auxiliary_key.key_timeout=st->current.key_timeout;
1659 st->current.key_timeout=st->now+st->key_lifetime;
1660 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1661 transport_peers_copy(st,&st->peers,&st->setup_peers);
1662 st->current.remote_session_id=st->setup_session_id;
1664 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1665 * But their mtu be unspecified, in which case we just use ours. */
1666 uint32_t intersite_mtu=
1667 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1668 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1670 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1671 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1672 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1673 enter_state_run(st);
1676 static void delete_one_key(struct site *st, struct data_key *key,
1677 cstring_t reason, cstring_t which, uint32_t loglevel)
1679 if (!is_transform_valid(key->transform)) return;
1680 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1681 dispose_transform(&key->transform);
1685 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1687 if (current_valid(st)) {
1688 slog(st,loglevel,"session closed (%s)",reason);
1690 delete_one_key(st,&st->current,0,0,0);
1691 set_link_quality(st);
1693 delete_one_key(st,&st->auxiliary_key,0,0,0);
1696 static void state_assert(struct site *st, bool_t ok)
1698 if (!ok) fatal("site:state_assert");
1701 static void enter_state_stop(struct site *st)
1703 st->state=SITE_STOP;
1705 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1706 dispose_transform(&st->new_transform);
1709 static void set_link_quality(struct site *st)
1712 if (current_valid(st))
1713 quality=LINK_QUALITY_UP;
1714 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1715 quality=LINK_QUALITY_DOWN;
1716 else if (st->addresses)
1717 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1718 else if (transport_peers_valid(&st->peers))
1719 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1721 quality=LINK_QUALITY_DOWN;
1723 st->netlink->set_quality(st->netlink->st,quality);
1726 static void enter_state_run(struct site *st)
1728 slog(st,LOG_STATE,"entering state RUN%s",
1729 current_valid(st) ? " (keyed)" : " (unkeyed)");
1733 st->setup_session_id=0;
1734 transport_peers_clear(st,&st->setup_peers);
1735 keyset_dispose(&st->peerkeys_kex);
1736 FILLZERO(st->localN);
1737 FILLZERO(st->remoteN);
1738 dispose_transform(&st->new_transform);
1739 memset(st->dhsecret,0,st->dh->len);
1740 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1741 set_link_quality(st);
1743 if (st->keepalive && !current_valid(st))
1744 initiate_key_setup(st, "keepalive", 0);
1747 static bool_t ensure_resolving(struct site *st)
1749 /* Reentrancy hazard: may call site_resolve_callback and hence
1750 * enter_new_state, enter_state_* and generate_msg*. */
1751 if (st->resolving_count)
1754 assert(st->addresses);
1756 /* resolver->request might reentrantly call site_resolve_callback
1757 * which will decrement st->resolving, so we need to increment it
1758 * twice beforehand to prevent decrement from thinking we're
1759 * finished, and decrement it ourselves. Alternatively if
1760 * everything fails then there are no callbacks due and we simply
1761 * set it to 0 and return false.. */
1762 st->resolving_n_results_stored=0;
1763 st->resolving_n_results_all=0;
1764 st->resolving_count+=2;
1765 const char **addrp=st->addresses;
1766 const char *address;
1768 for (; (address=*addrp++); ) {
1769 bool_t ok = st->resolver->request(st->resolver->st,address,
1770 st->remoteport,st->comms[0],
1771 site_resolve_callback,st);
1773 st->resolving_count++;
1777 st->resolving_count=0;
1780 decrement_resolving_count(st,2);
1784 static bool_t enter_state_resolve(struct site *st)
1786 /* Reentrancy hazard! See ensure_resolving. */
1787 state_assert(st,st->state==SITE_RUN);
1788 slog(st,LOG_STATE,"entering state RESOLVE");
1789 st->state=SITE_RESOLVE;
1790 return ensure_resolving(st);
1793 static bool_t enter_new_state(struct site *st, uint32_t next,
1794 const struct msg *prompt
1795 /* may be 0 for SENTMSG1 */)
1797 bool_t (*gen)(struct site *st, const struct msg *prompt);
1800 slog(st,LOG_STATE,"entering state %s",state_name(next));
1803 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1804 if (!kex_init(st)) return False;
1806 st->msg1_crossed_logged = False;
1809 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1810 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1811 if (!kex_init(st)) return False;
1815 state_assert(st,st->state==SITE_SENTMSG1);
1816 BUF_FREE(&st->buffer);
1820 state_assert(st,st->state==SITE_SENTMSG2);
1821 BUF_FREE(&st->buffer);
1825 state_assert(st,st->state==SITE_SENTMSG3);
1826 BUF_FREE(&st->buffer);
1830 state_assert(st,st->state==SITE_SENTMSG4);
1831 BUF_FREE(&st->buffer);
1836 fatal("enter_new_state(%s): invalid new state",state_name(next));
1840 if (hacky_par_start_failnow()) return False;
1842 r= gen(st,prompt) && send_msg(st);
1845 st->setup_retries, st->setup_retry_interval,
1850 if (next==SITE_RUN) {
1851 BUF_FREE(&st->buffer); /* Never reused */
1852 st->timeout=0; /* Never retransmit */
1853 activate_new_key(st);
1857 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1858 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1859 in either state, and enter_state_wait() will
1861 enter_state_wait(st);
1865 /* msg7 tells our peer that we're about to forget our key */
1866 static bool_t send_msg7(struct site *st, cstring_t reason)
1868 cstring_t transform_err;
1870 if (current_valid(st) && st->buffer.free
1871 && transport_peers_valid(&st->peers)) {
1872 BUF_ALLOC(&st->buffer,"site:MSG7");
1873 buffer_init(&st->buffer,calculate_max_start_pad());
1874 buf_append_uint32(&st->buffer,LABEL_MSG7);
1875 buf_append_string(&st->buffer,reason);
1876 if (call_transform_forwards(st, st->current.transform,
1877 &st->buffer, &transform_err))
1879 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1880 buf_prepend_uint32(&st->buffer,st->index);
1881 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1882 transport_xmit(st,&st->peers,&st->buffer,True);
1883 BUF_FREE(&st->buffer);
1890 /* We go into this state if our peer becomes uncommunicative. Similar to
1891 the "stop" state, we forget all session keys for a while, before
1892 re-entering the "run" state. */
1893 static void enter_state_wait(struct site *st)
1895 slog(st,LOG_STATE,"entering state WAIT");
1896 st->timeout=st->now+wait_timeout(st);
1897 st->state=SITE_WAIT;
1898 set_link_quality(st);
1899 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1900 /* XXX Erase keys etc. */
1903 static void generate_prod(struct site *st, struct buffer_if *buf)
1906 buf_append_uint32(buf,0);
1907 buf_append_uint32(buf,0);
1908 buf_append_uint32(buf,LABEL_PROD);
1909 buf_append_string(buf,st->localname);
1910 buf_append_string(buf,st->remotename);
1913 static void generate_send_prod(struct site *st,
1914 const struct comm_addr *source)
1916 if (!st->allow_send_prod) return; /* too soon */
1917 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1918 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1920 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1921 st->allow_send_prod=0;
1922 generate_prod(st,&st->scratch);
1923 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1924 dump_packet(st,&st->scratch,source,False,ok);
1927 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1930 int64_t offset=timeout-*now;
1931 if (offset<0) offset=0;
1932 if (offset>INT_MAX) offset=INT_MAX;
1933 if (*timeout_io<0 || offset<*timeout_io)
1938 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1941 struct site *st=sst;
1943 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1946 /* Work out when our next timeout is. The earlier of 'timeout' or
1947 'current.key_timeout'. A stored value of '0' indicates no timeout
1949 site_settimeout(st->timeout, timeout_io);
1950 site_settimeout(st->current.key_timeout, timeout_io);
1951 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1953 return 0; /* success */
1956 static void check_expiry(struct site *st, struct data_key *key,
1959 if (key->key_timeout && *now>key->key_timeout) {
1960 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1964 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1965 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1967 struct site *st=sst;
1970 if (st->timeout && *now>st->timeout) {
1972 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1973 if (!hacky_par_start_failnow())
1975 } else if (st->state==SITE_WAIT) {
1976 enter_state_run(st);
1978 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1982 check_expiry(st,&st->current,"current key");
1983 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1986 /* This function is called by the netlink device to deliver packets
1987 intended for the remote network. The packet is in "raw" wire
1988 format, but is guaranteed to be word-aligned. */
1989 static void site_outgoing(void *sst, struct buffer_if *buf)
1991 struct site *st=sst;
1992 cstring_t transform_err;
1994 if (st->state==SITE_STOP) {
1999 st->allow_send_prod=1;
2001 /* In all other states we consider delivering the packet if we have
2002 a valid key and a valid address to send it to. */
2003 if (current_valid(st) && transport_peers_valid(&st->peers)) {
2004 /* Transform it and send it */
2006 buf_prepend_uint32(buf,LABEL_MSG9);
2007 if (call_transform_forwards(st, st->current.transform,
2008 buf, &transform_err))
2010 buf_prepend_uint32(buf,LABEL_MSG0);
2011 buf_prepend_uint32(buf,st->index);
2012 buf_prepend_uint32(buf,st->current.remote_session_id);
2013 transport_xmit(st,&st->peers,buf,False);
2020 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
2022 initiate_key_setup(st,"outgoing packet",0);
2025 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
2026 uint32_t type, struct msg *m,
2027 struct priomsg *whynot)
2028 /* For packets which are identified by the local and remote names.
2029 * If it has our name and our peer's name in it it's for us. */
2031 struct buffer_if buf[1];
2032 buffer_readonly_clone(buf,buf_in);
2034 if (!unpick_msg(st,type,buf,m)) {
2035 priomsg_update_fixed(whynot, comm_notify_whynot_unpick, "malformed");
2038 #define NAME_MATCHES(lr) \
2039 if (!name_matches(&m->lr, st->lr##name)) { \
2040 if (priomsg_update_fixed(whynot, comm_notify_whynot_name_##lr, \
2041 "unknown " #lr " name: ")) { \
2042 truncmsg_add_packet_string(&whynot->m, m->lr.len, m->lr.name); \
2046 NAME_MATCHES(remote);
2047 NAME_MATCHES(local );
2053 static bool_t we_have_priority(struct site *st, const struct msg *m) {
2054 if (st->local_capabilities & m->remote_capabilities &
2055 CAPAB_PRIORITY_MOBILE) {
2056 if (st->local_mobile) return True;
2057 if (st-> peer_mobile) return False;
2059 return st->our_name_later;
2062 static bool_t setup_late_msg_ok(struct site *st,
2063 const struct buffer_if *buf_in,
2065 const struct comm_addr *source,
2066 struct msg *m /* returned */) {
2067 /* For setup packets which seem from their type like they are
2068 * late. Maybe they came via a different path. All we do is make
2069 * a note of the sending address, iff they look like they are part
2070 * of the current key setup attempt. */
2071 if (!named_for_us(st,buf_in,msgtype,m,0))
2072 /* named_for_us calls unpick_msg which gets the nonces */
2074 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
2075 !consttime_memeq(m->nL,st->localN, NONCELEN))
2076 /* spoof ? from stale run ? who knows */
2078 transport_setup_msgok(st,source);
2082 /* This function is called by the communication device to deliver
2083 packets from our peers.
2084 It should return True if the packet is recognised as being for
2085 this current site instance (and should therefore not be processed
2086 by other sites), even if the packet was otherwise ignored. */
2087 static bool_t site_incoming(void *sst, struct buffer_if *buf,
2088 const struct comm_addr *source,
2089 struct priomsg *whynot)
2091 struct site *st=sst;
2093 if (buf->size < 12) return False;
2095 uint32_t dest=get_uint32(buf->start);
2096 uint32_t msgtype=get_uint32(buf->start+8);
2098 /* initialised by named_for_us, or process_msgN for N!=1 */
2100 if (msgtype==LABEL_MSG1) {
2101 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2103 /* It's a MSG1 addressed to us. Decide what to do about it. */
2104 dump_packet(st,buf,source,True,True);
2105 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
2106 st->state==SITE_WAIT) {
2107 /* We should definitely process it */
2108 transport_compute_setupinit_peers(st,0,0,source);
2109 if (process_msg1(st,buf,source,&msg)) {
2110 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
2111 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
2112 if (entered && st->addresses && st->local_mobile)
2113 /* We must do this as the very last thing, because
2114 the resolver callback might reenter us. */
2115 ensure_resolving(st);
2117 slog(st,LOG_ERROR,"failed to process incoming msg1");
2121 } else if (st->state==SITE_SENTMSG1) {
2122 /* We've just sent a message 1! They may have crossed on
2123 the wire. If we have priority then we ignore the
2124 incoming one, otherwise we process it as usual. */
2125 if (we_have_priority(st,&msg)) {
2127 if (!st->msg1_crossed_logged++)
2128 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
2129 "priority => ignore incoming msg1");
2132 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
2133 "priority => use incoming msg1");
2134 if (process_msg1(st,buf,source,&msg)) {
2135 BUF_FREE(&st->buffer); /* Free our old message 1 */
2136 transport_setup_msgok(st,source);
2137 enter_new_state(st,SITE_SENTMSG2,&msg);
2139 slog(st,LOG_ERROR,"failed to process an incoming "
2140 "crossed msg1 (we have low priority)");
2145 } else if (st->state==SITE_SENTMSG2 ||
2146 st->state==SITE_SENTMSG4) {
2147 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
2148 /* We are ahead in the protocol, but that msg1 had the
2149 * peer's nonce so presumably it is from this key
2150 * exchange run, via a slower route */
2151 transport_setup_msgok(st,source);
2153 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
2158 /* The message 1 was received at an unexpected stage of the
2159 key setup. Well, they lost the race. */
2160 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
2164 if (msgtype==LABEL_PROD) {
2165 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2167 dump_packet(st,buf,source,True,True);
2168 if (st->state!=SITE_RUN) {
2169 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
2170 } else if (current_valid(st)) {
2171 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
2173 initiate_key_setup(st,"peer sent PROD packet",source);
2178 if (dest==st->index) {
2179 /* Explicitly addressed to us */
2180 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
2183 /* If the source is our current peer then initiate a key setup,
2184 because our peer's forgotten the key */
2185 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
2187 initiated = initiate_key_setup(st,"received a NAK",source);
2188 if (!initiated) generate_send_prod(st,source);
2190 slog(st,LOG_SEC,"bad incoming NAK");
2194 process_msg0(st,buf,source);
2197 /* Setup packet: should not have been explicitly addressed
2199 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2202 /* Setup packet: expected only in state SENTMSG1 */
2203 if (st->state!=SITE_SENTMSG1) {
2204 if ((st->state==SITE_SENTMSG3 ||
2205 st->state==SITE_SENTMSG5) &&
2206 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2208 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
2209 } else if (process_msg2(st,buf,source,&msg)) {
2210 transport_setup_msgok(st,source);
2211 enter_new_state(st,SITE_SENTMSG3,&msg);
2213 slog(st,LOG_SEC,"invalid MSG2");
2216 case CASES_MSG3_KNOWN:
2217 /* Setup packet: expected only in state SENTMSG2 */
2218 if (st->state!=SITE_SENTMSG2) {
2219 if ((st->state==SITE_SENTMSG4) &&
2220 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2222 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2223 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2224 transport_setup_msgok(st,source);
2225 enter_new_state(st,SITE_SENTMSG4,&msg);
2227 slog(st,LOG_SEC,"invalid MSG3");
2231 /* Setup packet: expected only in state SENTMSG3 */
2232 if (st->state!=SITE_SENTMSG3) {
2233 if ((st->state==SITE_SENTMSG5) &&
2234 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2236 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2237 } else if (process_msg4(st,buf,source,&msg)) {
2238 transport_setup_msgok(st,source);
2239 enter_new_state(st,SITE_SENTMSG5,&msg);
2241 slog(st,LOG_SEC,"invalid MSG4");
2245 /* Setup packet: expected only in state SENTMSG4 */
2246 /* (may turn up in state RUN if our return MSG6 was lost
2247 and the new key has already been activated. In that
2248 case we discard it. The peer will realise that we
2249 are using the new key when they see our data packets.
2250 Until then the peer's data packets to us get discarded. */
2251 if (st->state==SITE_SENTMSG4) {
2252 if (process_msg5(st,buf,source,st->new_transform)) {
2253 transport_setup_msgok(st,source);
2254 enter_new_state(st,SITE_RUN,&msg);
2256 slog(st,LOG_SEC,"invalid MSG5");
2258 } else if (st->state==SITE_RUN) {
2259 if (process_msg5(st,buf,source,st->current.transform)) {
2260 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2261 transport_setup_msgok(st,source);
2262 create_msg6(st,st->current.transform,
2263 st->current.remote_session_id);
2264 transport_xmit(st,&st->peers,&st->buffer,True);
2265 BUF_FREE(&st->buffer);
2267 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2270 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2274 /* Setup packet: expected only in state SENTMSG5 */
2275 if (st->state!=SITE_SENTMSG5) {
2276 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2277 } else if (process_msg6(st,buf,source)) {
2278 BUF_FREE(&st->buffer); /* Free message 5 */
2279 transport_setup_msgok(st,source);
2280 activate_new_key(st);
2282 slog(st,LOG_SEC,"invalid MSG6");
2286 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2294 priomsg_update_fixed(whynot, comm_notify_whynot_general,
2295 "not MSG1 or PROD; unknown dest index");
2299 static void site_control(void *vst, bool_t run)
2301 struct site *st=vst;
2302 if (run) enter_state_run(st);
2303 else enter_state_stop(st);
2306 static void site_phase_hook(void *sst, uint32_t newphase)
2308 struct site *st=sst;
2310 /* The program is shutting down; tell our peer */
2311 send_msg7(st,"shutting down");
2314 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2316 struct site *st=sst;
2317 dispose_transform(&st->current.transform);
2318 dispose_transform(&st->auxiliary_key.transform);
2319 dispose_transform(&st->new_transform);
2320 /* Not much point overwiting the signing key, since we loaded it
2321 from disk, and it is only valid prospectively if at all,
2323 /* XXX it would be best to overwrite the DH state, because that
2324 _is_ relevant to forward secrecy. However we have no
2325 convenient interface for doing that and in practice gmp has
2326 probably dribbled droppings all over the malloc arena. A good
2327 way to fix this would be to have a privsep child for asymmetric
2328 crypto operations, but that's a task for another day. */
2331 static void setup_sethash(struct site *st, dict_t *dict,
2332 struct hash_if **hash, struct cloc loc,
2333 sig_sethash_fn *sethash, void *sigkey_st) {
2334 if (!*hash) *hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2335 sethash(sigkey_st,*hash);
2337 #define SETUP_SETHASH(k) do{ \
2339 setup_sethash(st,dict, &hash,loc, (k)->sethash,(k)->st); \
2342 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2345 static uint32_t index_sequence;
2353 st->cl.description="site";
2354 st->cl.type=CL_SITE;
2356 st->cl.interface=&st->ops;
2358 st->ops.control=site_control;
2359 st->ops.status=site_status;
2360 st->peerkeys_path=0;
2361 st->peerkeys_tmpl.buffer=0;
2362 st->peerkeys_current=st->peerkeys_kex=0;
2364 /* First parameter must be a dict */
2365 item=list_elem(args,0);
2366 if (!item || item->type!=t_dict)
2367 cfgfatal(loc,"site","parameter must be a dictionary\n");
2369 dict=item->data.dict;
2370 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2371 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2373 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2375 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2377 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2379 /* Sanity check (which also allows the 'sites' file to include
2380 site() closures for all sites including our own): refuse to
2381 talk to ourselves */
2382 if (strcmp(st->localname,st->remotename)==0) {
2383 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2385 if (st->peer_mobile != st->local_mobile)
2386 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2387 " but our local-mobile=%d\n",
2388 st->localname, st->peer_mobile, st->local_mobile);
2392 if (st->peer_mobile && st->local_mobile) {
2393 Message(M_WARNING,"site %s: site is mobile but so are we"
2394 " -> ignoring this site\n", st->remotename);
2399 assert(index_sequence < 0xffffffffUL);
2400 st->index = ++index_sequence;
2401 st->local_capabilities = 0;
2402 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2403 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2405 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2406 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2407 if (!things##_cfg) \
2408 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2409 st->nthings=list_length(things##_cfg); \
2410 NEW_ARY(st->things,st->nthings); \
2411 assert(st->nthings); \
2412 for (i=0; i<st->nthings; i++) { \
2413 item_t *item=list_elem(things##_cfg,i); \
2414 if (item->type!=t_closure) \
2415 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2416 closure_t *cl=item->data.closure; \
2417 if (cl->type!=CL_TYPE) \
2418 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2419 st->things[i]=cl->interface; \
2423 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2425 NEW_ARY(st->commclientinfos, st->ncomms);
2426 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2427 for (i=0; i<st->ncomms; i++) {
2428 st->commclientinfos[i] =
2430 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2433 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2434 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2435 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2437 struct hash_if *hash=0;
2439 st->privkeys=find_cl_if(dict,"key-cache",CL_PRIVCACHE,False,"site",loc);
2440 if (!st->privkeys) {
2442 find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2443 SETUP_SETHASH(st->privkey_fixed);
2446 struct sigpubkey_if *fixed_pubkey
2447 =find_cl_if(dict,"key",CL_SIGPUBKEY,False,"site",loc);
2448 st->peerkeys_path=dict_read_string(dict,"peer-keys",fixed_pubkey==0,
2450 if (st->peerkeys_path) {
2451 pathprefix_template_init(&st->peerkeys_tmpl,st->peerkeys_path,
2452 PEERKEYS_SUFFIX_MAXLEN + 1 /* nul */);
2453 st->peerkeys_current=keyset_load(st->peerkeys_path,
2454 &st->scratch,st->log,M_ERR);
2456 fixed_pubkey->dispose(fixed_pubkey->st);
2459 assert(fixed_pubkey);
2460 SETUP_SETHASH(fixed_pubkey);
2461 NEW(st->peerkeys_current);
2462 st->peerkeys_current->refcount=1;
2463 st->peerkeys_current->nkeys=1;
2464 st->peerkeys_current->keys[0].id=keyid_zero;
2465 st->peerkeys_current->keys[0].pubkey=fixed_pubkey;
2466 slog(st,LOG_SIGKEYS,
2467 "using old-style fixed peer public key (no `peer-keys')");
2470 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2472 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2473 else st->remoteport=0;
2475 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2477 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2479 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2480 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2481 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2483 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2484 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2485 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2486 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2487 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2489 st->mobile_peer_expiry= dict_read_number(
2490 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2492 const char *peerskey= st->peer_mobile
2493 ? "mobile-peers-max" : "static-peers-max";
2494 st->transport_peers_max= dict_read_number(
2495 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2496 if (st->transport_peers_max<1 ||
2497 st->transport_peers_max>MAX_PEER_ADDRS) {
2498 cfgfatal(loc,"site", "%s must be in range 1.."
2499 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2502 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2503 st->key_renegotiate_time=st->key_lifetime/2;
2505 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2506 st->key_renegotiate_time=dict_read_number(
2507 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2508 if (st->key_renegotiate_time > st->key_lifetime) {
2509 cfgfatal(loc,"site",
2510 "renegotiate-time must be less than key-lifetime\n");
2513 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2514 log_event_table,"site");
2516 st->resolving_count=0;
2517 st->allow_send_prod=0;
2519 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2521 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2523 /* The information we expect to see in incoming messages of type 1 */
2524 /* fixme: lots of unchecked overflows here, but the results are only
2525 corrupted packets rather than undefined behaviour */
2526 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2528 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2530 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2531 BUF_ALLOC(&st->scratch,"site:scratch");
2533 /* We are interested in poll(), but only for timeouts. We don't have
2534 any fds of our own. */
2535 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2538 st->remote_capabilities=0;
2539 st->chosen_transform=0;
2540 st->current.key_timeout=0;
2541 st->auxiliary_key.key_timeout=0;
2542 transport_peers_clear(st,&st->peers);
2543 transport_peers_clear(st,&st->setup_peers);
2544 /* XXX mlock these */
2545 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2546 st->sharedsecretlen=st->sharedsecretallocd=0;
2549 #define SET_CAPBIT(bit) do { \
2550 uint32_t capflag = 1UL << (bit); \
2551 if (st->local_capabilities & capflag) \
2552 slog(st,LOG_ERROR,"capability bit" \
2553 " %d (%#"PRIx32") reused", (bit), capflag); \
2554 st->local_capabilities |= capflag; \
2557 for (i=0; i<st->ntransforms; i++)
2558 SET_CAPBIT(st->transforms[i]->capab_bit);
2562 if (st->local_mobile || st->peer_mobile)
2563 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2565 /* We need to register the remote networks with the netlink device */
2566 uint32_t netlink_mtu; /* local virtual interface mtu */
2567 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2568 if (!st->mtu_target)
2569 st->mtu_target=netlink_mtu;
2571 for (i=0; i<st->ncomms; i++)
2572 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2574 st->current.transform=0;
2575 st->auxiliary_key.transform=0;
2576 st->new_transform=0;
2577 st->auxiliary_is_new=0;
2579 enter_state_stop(st);
2581 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2582 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2584 return new_closure(&st->cl);
2587 void site_module(dict_t *dict)
2589 add_closure(dict,"site",site_apply);
2593 /***** TRANSPORT PEERS definitions *****/
2595 static void transport_peers_debug(struct site *st, transport_peers *dst,
2596 const char *didwhat,
2597 int nargs, const struct comm_addr *args,
2602 if (!(st->log_events & LOG_PEER_ADDRS))
2603 return; /* an optimisation */
2605 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2606 (dst==&st->peers ? "data" :
2607 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2608 didwhat, nargs, dst->npeers);
2610 for (i=0, argp=(void*)args;
2612 i++, (argp+=stride?stride:sizeof(*args))) {
2613 const struct comm_addr *ca=(void*)argp;
2614 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2615 i, comm_addr_to_string(ca));
2617 for (i=0; i<dst->npeers; i++) {
2618 struct timeval diff;
2619 timersub(tv_now,&dst->peers[i].last,&diff);
2620 const struct comm_addr *ca=&dst->peers[i].addr;
2621 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2622 i, comm_addr_to_string(ca),
2623 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2627 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2628 /* peers must be sorted first */
2629 int previous_peers=peers->npeers;
2630 struct timeval oldest;
2631 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2632 oldest.tv_usec = tv_now->tv_usec;
2633 while (peers->npeers>1 &&
2634 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2636 if (peers->npeers != previous_peers)
2637 transport_peers_debug(st,peers,"expire", 0,0,0);
2640 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2641 const struct comm_addr *ca,
2642 const struct timeval *tv) {
2643 /* returns false if output is full */
2646 if (peers->npeers >= st->transport_peers_max)
2649 for (search=0; search<peers->npeers; search++)
2650 if (comm_addr_equal(&peers->peers[search].addr, ca))
2653 peers->peers[peers->npeers].addr = *ca;
2654 peers->peers[peers->npeers].last = *tv;
2659 static void transport_record_peers(struct site *st, transport_peers *peers,
2660 const struct comm_addr *addrs, int naddrs,
2662 /* We add addrs into peers. The new entries end up at the front
2663 * and displace entries towards the end (perhaps even off the
2664 * end). Any existing matching entries are moved up to the front.
2666 * Caller must first call transport_peers_expire. */
2669 /* avoids debug for uninteresting updates */
2671 for (i=0; i<peers->npeers; i++) {
2672 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2673 memmove(peers->peers+1, peers->peers,
2674 sizeof(peers->peers[0]) * i);
2675 peers->peers[0].addr = addrs[0];
2676 peers->peers[0].last = *tv_now;
2682 int old_npeers=peers->npeers;
2683 transport_peer old_peers[old_npeers];
2684 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2688 for (i=0; i<naddrs; i++) {
2689 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2692 for (i=0; i<old_npeers; i++) {
2693 const transport_peer *old=&old_peers[i];
2694 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2698 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2701 static void transport_expire_record_peers(struct site *st,
2702 transport_peers *peers,
2703 const struct comm_addr *addrs,
2704 int naddrs, const char *m) {
2705 /* Convenience function */
2706 transport_peers_expire(st,peers);
2707 transport_record_peers(st,peers,addrs,naddrs,m);
2710 static bool_t transport_compute_setupinit_peers(struct site *st,
2711 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2712 int n_configured_addrs /* 0 if none or not found */,
2713 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2714 if (!n_configured_addrs && !incoming_packet_addr &&
2715 !transport_peers_valid(&st->peers))
2718 slog(st,LOG_SETUP_INIT,
2719 "using: %d configured addr(s);%s %d old peer addrs(es)",
2721 incoming_packet_addr ? " incoming packet address;" : "",
2724 /* Non-mobile peers try addresses until one is plausible. The
2725 * effect is that this code always tries first the configured
2726 * address if supplied, or otherwise the address of the incoming
2727 * PROD, or finally the existing data peer if one exists; this is
2730 transport_peers_copy(st,&st->setup_peers,&st->peers);
2731 transport_peers_expire(st,&st->setup_peers);
2733 if (incoming_packet_addr)
2734 transport_record_peers(st,&st->setup_peers,
2735 incoming_packet_addr,1, "incoming");
2737 if (n_configured_addrs)
2738 transport_record_peers(st,&st->setup_peers,
2739 configured_addrs,n_configured_addrs, "setupinit");
2741 assert(transport_peers_valid(&st->setup_peers));
2745 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2746 if (st->peer_mobile)
2747 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2749 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2750 if (st->peer_mobile)
2751 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2754 static int transport_peers_valid(transport_peers *peers) {
2755 return peers->npeers;
2757 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2759 transport_peers_debug(st,peers,"clear",0,0,0);
2761 static void transport_peers_copy(struct site *st, transport_peers *dst,
2762 const transport_peers *src) {
2763 dst->npeers=src->npeers;
2764 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2765 transport_peers_debug(st,dst,"copy",
2766 src->npeers, &src->peers->addr, sizeof(*src->peers));
2769 static void transport_resolve_complete(struct site *st,
2770 const struct comm_addr *addrs,
2772 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2774 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2778 static void transport_resolve_complete_tardy(struct site *st,
2779 const struct comm_addr *addrs,
2781 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2782 "resolved tardily");
2785 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2787 const transport_peers *inp) {
2788 /* out and in->peers may be the same region, or nonoverlapping */
2789 const transport_peer *in=inp->peers;
2791 for (slot=0; slot<inp->npeers; slot++) {
2792 if (!(mask & (1U << slot)))
2794 if (!(out==in && slot==*nout_io))
2795 COPY_OBJ(out[*nout_io], in[slot]);
2800 void transport_xmit(struct site *st, transport_peers *peers,
2801 struct buffer_if *buf, bool_t candebug) {
2803 transport_peers_expire(st, peers);
2804 unsigned failed=0; /* bitmask */
2805 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2808 for (slot=0; slot<peers->npeers; slot++) {
2809 transport_peer *peer=&peers->peers[slot];
2810 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2812 dump_packet(st, buf, &peer->addr, False, ok);
2814 failed |= 1U << slot;
2817 if (ok && !st->peer_mobile)
2820 /* Now we need to demote/delete failing addrs: if we are mobile we
2821 * merely demote them; otherwise we delete them. */
2822 if (st->local_mobile) {
2823 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2824 /* `expected' has all the failures at the end already */
2825 if (failed != expected) {
2827 transport_peer failedpeers[nfailed];
2828 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2829 assert(fslot == nfailed);
2831 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2832 assert(wslot+nfailed == peers->npeers);
2833 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2834 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2837 if (failed && peers->npeers > 1) {
2839 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2840 peers->npeers=wslot;
2841 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2846 /***** END of transport peers declarations *****/