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 slog(st,LOG_SIGKEYS,"using private key " SIGKEYID_PR_FMT,
715 SIGKEYID_PR_VAL(prompt->pubkeys_accepted[ki]));
716 buf_append_uint8(&st->buffer,ki);
719 append_string_xinfo_done(&st->buffer,&xia);
721 buf_append_string(&st->buffer,st->remotename);
722 BUF_ADD_OBJ(append,&st->buffer,st->localN);
723 if (type==LABEL_MSG1) return True;
724 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
725 if (type==LABEL_MSG2) return True;
727 if (hacky_par_mid_failnow()) return False;
729 if (MSGMAJOR(type) == 3) do {
730 minor = MSGMINOR(type);
731 if (minor < 1) break;
732 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
735 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
736 buf_append_string(&st->buffer,dhpub);
739 bool_t ok=privkey->sign(privkey->st,
750 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
753 nm->len=buf_unprepend_uint16(msg);
754 CHECK_AVAIL(msg,nm->len);
755 nm->name=buf_unprepend(msg,nm->len);
756 uint8_t *nul=memchr(nm->name,0,nm->len);
758 buffer_readonly_view(&nm->extrainfo,0,0);
760 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
761 nm->len=nul-nm->name;
766 static bool_t unpick_msg(struct site *st, uint32_t type,
767 struct buffer_if *msg, struct msg *m)
771 m->n_pubkeys_accepted_nom=-1;
772 m->capab_transformnum=-1;
773 m->signing_key_index=-1;
774 m->hashstart=msg->start;
776 m->dest=buf_unprepend_uint32(msg);
778 m->source=buf_unprepend_uint32(msg);
779 CHECK_TYPE(msg,type);
780 if (!unpick_name(msg,&m->remote)) return False;
781 m->remote_capabilities=0;
783 if (m->remote.extrainfo.size) {
784 CHECK_AVAIL(&m->remote.extrainfo,4);
785 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
787 if (type_is_msg34(type) && m->remote.extrainfo.size) {
788 CHECK_AVAIL(&m->remote.extrainfo,2);
789 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
791 if (type_is_msg23(type) && m->remote.extrainfo.size) {
792 m->n_pubkeys_accepted_nom = buf_unprepend_uint8(&m->remote.extrainfo);
793 if (!m->n_pubkeys_accepted_nom) return False;
794 for (int ki_nom=0; ki_nom<m->n_pubkeys_accepted_nom; ki_nom++) {
795 CHECK_AVAIL(&m->remote.extrainfo,KEYIDSZ);
796 struct sigkeyid *kid = buf_unprepend(&m->remote.extrainfo,KEYIDSZ);
797 if (ki_nom<MAX_SIG_KEYS) m->pubkeys_accepted[ki_nom] = kid;
800 m->n_pubkeys_accepted_nom = 1;
801 m->pubkeys_accepted[0] = &keyid_zero;
803 if (type_is_msg34(type) && m->remote.extrainfo.size) {
804 m->signing_key_index=buf_unprepend_uint8(&m->remote.extrainfo);
806 m->signing_key_index=0;
808 if (!unpick_name(msg,&m->local)) return False;
809 if (type==LABEL_PROD) {
813 CHECK_AVAIL(msg,NONCELEN);
814 m->nR=buf_unprepend(msg,NONCELEN);
815 if (type==LABEL_MSG1) {
819 CHECK_AVAIL(msg,NONCELEN);
820 m->nL=buf_unprepend(msg,NONCELEN);
821 if (type==LABEL_MSG2) {
825 if (MSGMAJOR(type) == 3) do {
826 minor = MSGMINOR(type);
827 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
828 if (minor < (minminor)) \
829 m->capab_##kind##num = (dflt); \
831 CHECK_AVAIL(msg, 1); \
832 m->capab_##kind##num = buf_unprepend_uint8(msg); \
835 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
836 #undef MAYBE_READ_CAP
839 m->pklen=buf_unprepend_uint16(msg);
840 CHECK_AVAIL(msg,m->pklen);
841 m->pk=buf_unprepend(msg,m->pklen);
842 m->hashlen=msg->start-m->hashstart;
844 if (m->signing_key_index < 0 ||
845 m->signing_key_index >= st->peerkeys_kex->nkeys) {
848 struct sigpubkey_if *pubkey=
849 st->peerkeys_kex->keys[m->signing_key_index].pubkey;
850 if (!pubkey->unpick(pubkey->st,msg,&m->sig)) {
859 static bool_t name_matches(const struct parsedname *nm, const char *expected)
861 int expected_len=strlen(expected);
863 nm->len == expected_len &&
864 !memcmp(nm->name, expected, expected_len);
867 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
870 if (type==LABEL_MSG1) return True;
872 /* Check that the site names and our nonce have been sent
873 back correctly, and then store our peer's nonce. */
874 if (!name_matches(&m->remote,st->remotename)) {
875 *error="wrong remote site name";
878 if (!name_matches(&m->local,st->localname)) {
879 *error="wrong local site name";
882 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
883 *error="wrong locally-generated nonce";
886 if (type==LABEL_MSG2) return True;
887 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
888 *error="wrong remotely-generated nonce";
891 /* MSG3 has complicated rules about capabilities, which are
892 * handled in process_msg3. */
893 if (MSGMAJOR(type) == 3) return True;
894 if (m->remote_capabilities!=st->remote_capabilities) {
895 *error="remote capabilities changed";
898 if (type==LABEL_MSG4) return True;
899 *error="unknown message type";
903 static void peerkeys_maybe_incorporate(struct site *st, const char *file,
904 const char *whatmore,
907 struct peer_keyset *atsuffix=
908 keyset_load(file,&st->scratch,st->log,logcl_enoent,st->defhash);
909 if (!atsuffix) return;
911 if (st->peerkeys_current &&
912 serial_cmp(atsuffix->serial,st->peerkeys_current->serial) <= 0) {
913 slog(st,LOG_SIGKEYS,"keys from %s%s are older, discarding",
915 keyset_dispose(&atsuffix);
917 if (r) slog(st,LOG_ERROR,"failed to remove old key update %s: %s\n",
918 st->peerkeys_tmpl.buffer,strerror(errno));
921 slog(st,LOG_SIGKEYS,"keys from %s%s are newer, installing",
923 keyset_dispose(&st->peerkeys_current);
924 st->peerkeys_current=atsuffix;
925 int r=rename(file,st->peerkeys_path);
926 if (r) slog(st,LOG_ERROR,"failed to install key update %s as %s: %s\n",
927 st->peerkeys_tmpl.buffer,st->peerkeys_path,
932 static void peerkeys_check_for_update(struct site *st)
934 if (!st->peerkeys_path) return;
936 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~proc");
937 peerkeys_maybe_incorporate(st,st->peerkeys_tmpl.buffer,
938 " (found old update)",
941 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~update");
942 const char *inputp=st->peerkeys_tmpl.buffer;
943 if (access(inputp,R_OK)) {
945 slog(st,LOG_ERROR,"cannot access peer key update file %s\n",
950 buffer_init(&st->scratch,0);
951 BUF_ADD_BYTES(append,&st->scratch,
952 st->peerkeys_tmpl.buffer,
953 strlen(st->peerkeys_tmpl.buffer)+1);
954 inputp=st->scratch.start;
956 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~proc");
957 const char *oursp=st->peerkeys_tmpl.buffer;
959 int r=rename(inputp,oursp);
961 slog(st,LOG_ERROR,"failed to claim key update file %s as %s: %s",
962 inputp,oursp,strerror(errno));
966 peerkeys_maybe_incorporate(st,oursp," (update)",M_ERR);
970 static bool_t kex_init(struct site *st)
972 keyset_dispose(&st->peerkeys_kex);
973 peerkeys_check_for_update(st);
974 if (!st->peerkeys_current) {
975 slog(st,LOG_SETUP_INIT,"no peer public keys, abandoning key setup");
978 st->peerkeys_kex = keyset_dup(st->peerkeys_current);
979 st->random->generate(st->random->st,NONCELEN,st->localN);
983 static bool_t generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
986 generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
989 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
990 const struct comm_addr *src,
993 /* We've already determined we're in an appropriate state to
994 process an incoming MSG1, and that the MSG1 has correct values
997 st->setup_session_id=m->source;
998 st->remote_capabilities=m->remote_capabilities;
999 memcpy(st->remoteN,m->nR,NONCELEN);
1003 static bool_t generate_msg2(struct site *st,
1004 const struct msg *prompt_may_be_null)
1007 generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
1010 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
1011 const struct comm_addr *src,
1012 struct msg *m /* returned */)
1016 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
1017 if (!check_msg(st,LABEL_MSG2,m,&err)) {
1018 slog(st,LOG_SEC,"msg2: %s",err);
1021 st->setup_session_id=m->source;
1022 st->remote_capabilities=m->remote_capabilities;
1024 /* Select the transform to use */
1026 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
1027 if (!remote_crypto_caps)
1028 /* old secnets only had this one transform */
1029 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
1031 #define CHOOSE_CRYPTO(kind, whats) do { \
1032 struct kind##_if *iface; \
1033 uint32_t bit, ours = 0; \
1035 for (i= 0; i < st->n##kind##s; i++) { \
1036 iface=st->kind##s[i]; \
1037 bit = 1UL << iface->capab_bit; \
1038 if (bit & remote_crypto_caps) goto kind##_found; \
1041 slog(st,LOG_ERROR,"no " whats " in common" \
1042 " (us %#"PRIx32"; them: %#"PRIx32")", \
1043 st->local_capabilities & ours, remote_crypto_caps); \
1046 st->chosen_##kind = iface; \
1049 CHOOSE_CRYPTO(transform, "transforms");
1051 #undef CHOOSE_CRYPTO
1053 memcpy(st->remoteN,m->nR,NONCELEN);
1057 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
1059 /* Now we have our nonce and their nonce. Think of a secret key,
1060 and create message number 3. */
1061 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1062 return generate_msg(st,
1063 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
1066 "site:MSG3",prompt);
1069 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
1071 /* Check signature and store g^x mod m */
1074 if (m->signing_key_index >= 0) {
1075 if (m->signing_key_index >= st->peerkeys_kex->nkeys)
1077 ki=m->signing_key_index;
1079 for (ki=0; ki<st->peerkeys_kex->nkeys; ki++)
1080 if (sigkeyid_equal(&keyid_zero,&st->peerkeys_kex->keys[ki].id))
1084 "peer signed with keyid zero, which we do not accept");
1088 struct sigpubkey_if *pubkey=st->peerkeys_kex->keys[ki].pubkey;
1090 if (!pubkey->check(pubkey->st,
1091 m->hashstart,m->hashlen,
1093 slog(st,LOG_SEC,"msg3/msg4 signature failed check!"
1094 " (key " SIGKEYID_PR_FMT ")",
1095 SIGKEYID_PR_VAL(&st->peerkeys_kex->keys[ki].id));
1098 slog(st,LOG_SIGKEYS,"verified peer signature with key " SIGKEYID_PR_FMT,
1099 SIGKEYID_PR_VAL(&st->peerkeys_kex->keys[ki].id));
1101 st->remote_adv_mtu=m->remote_mtu;
1106 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
1107 const struct comm_addr *src, uint32_t msgtype,
1108 struct msg *m /* returned */)
1113 case CASES_MSG3_KNOWN: break;
1117 if (!unpick_msg(st,msgtype,msg3,m)) return False;
1118 if (!check_msg(st,msgtype,m,&err)) {
1119 slog(st,LOG_SEC,"msg3: %s",err);
1122 uint32_t capab_adv_late = m->remote_capabilities
1123 & ~st->remote_capabilities & st->early_capabilities;
1124 if (capab_adv_late) {
1125 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
1126 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
1127 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
1131 #define CHOSE_CRYPTO(kind, what) do { \
1132 struct kind##_if *iface; \
1134 for (i=0; i<st->n##kind##s; i++) { \
1135 iface=st->kind##s[i]; \
1136 if (iface->capab_bit == m->capab_##kind##num) \
1137 goto kind##_found; \
1139 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
1140 m->capab_##kind##num); \
1143 st->chosen_##kind=iface; \
1146 CHOSE_CRYPTO(transform, "transform");
1150 if (!process_msg3_msg4(st,m))
1153 /* Update our idea of the remote site's capabilities, now that we've
1154 * verified that its message was authentic.
1156 * Our previous idea of the remote site's capabilities came from the
1157 * unauthenticated MSG1. We've already checked that this new message
1158 * doesn't change any of the bits we relied upon in the past, but it may
1159 * also have set additional capability bits. We simply throw those away
1160 * now, and use the authentic capabilities from this MSG3. */
1161 st->remote_capabilities=m->remote_capabilities;
1163 /* Terminate their DH public key with a '0' */
1165 /* Invent our DH secret key */
1166 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1168 /* Generate the shared key and set up the transform */
1169 if (!set_new_transform(st,m->pk)) return False;
1174 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
1176 /* We have both nonces, their public key and our private key. Generate
1177 our public key, sign it and send it to them. */
1178 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
1181 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
1182 const struct comm_addr *src,
1183 struct msg *m /* returned */)
1187 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
1188 if (!check_msg(st,LABEL_MSG4,m,&err)) {
1189 slog(st,LOG_SEC,"msg4: %s",err);
1193 if (!process_msg3_msg4(st,m))
1196 /* Terminate their DH public key with a '0' */
1199 /* Generate the shared key and set up the transform */
1200 if (!set_new_transform(st,m->pk)) return False;
1211 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1214 CHECK_AVAIL(msg0,4);
1215 m->dest=buf_unprepend_uint32(msg0);
1216 CHECK_AVAIL(msg0,4);
1217 m->source=buf_unprepend_uint32(msg0);
1218 CHECK_AVAIL(msg0,4);
1219 m->type=buf_unprepend_uint32(msg0);
1221 /* Leaves transformed part of buffer untouched */
1224 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1226 cstring_t transform_err;
1228 BUF_ALLOC(&st->buffer,"site:MSG5");
1229 /* We are going to add four words to the message */
1230 buffer_init(&st->buffer,calculate_max_start_pad());
1231 /* Give the netlink code an opportunity to put its own stuff in the
1232 message (configuration information, etc.) */
1233 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1234 if (call_transform_forwards(st,st->new_transform,
1235 &st->buffer,&transform_err))
1237 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1238 buf_prepend_uint32(&st->buffer,st->index);
1239 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1241 st->retries=st->setup_retries;
1245 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1246 const struct comm_addr *src,
1247 struct transform_inst_if *transform)
1250 cstring_t transform_err;
1252 if (!unpick_msg0(st,msg5,&m)) return False;
1254 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1255 /* There's a problem */
1256 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1259 /* Buffer should now contain untransformed PING packet data */
1260 CHECK_AVAIL(msg5,4);
1261 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1262 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1265 /* Older versions of secnet used to write some config data here
1266 * which we ignore. So we don't CHECK_EMPTY */
1270 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1271 uint32_t session_id)
1273 cstring_t transform_err;
1275 BUF_ALLOC(&st->buffer,"site:MSG6");
1276 /* We are going to add four words to the message */
1277 buffer_init(&st->buffer,calculate_max_start_pad());
1278 /* Give the netlink code an opportunity to put its own stuff in the
1279 message (configuration information, etc.) */
1280 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1281 transform_apply_return problem =
1282 call_transform_forwards(st,transform,
1283 &st->buffer,&transform_err);
1285 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1286 buf_prepend_uint32(&st->buffer,st->index);
1287 buf_prepend_uint32(&st->buffer,session_id);
1290 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1292 if (!is_transform_valid(st->new_transform))
1294 create_msg6(st,st->new_transform,st->setup_session_id);
1295 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1299 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1300 const struct comm_addr *src)
1303 cstring_t transform_err;
1305 if (!unpick_msg0(st,msg6,&m)) return False;
1307 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1308 /* There's a problem */
1309 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1312 /* Buffer should now contain untransformed PING packet data */
1313 CHECK_AVAIL(msg6,4);
1314 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1315 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1318 /* Older versions of secnet used to write some config data here
1319 * which we ignore. So we don't CHECK_EMPTY */
1323 static transform_apply_return
1324 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1325 const struct comm_addr *src)
1327 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1329 transform_apply_return problem;
1331 if (!unpick_msg0(st,msg0,&m)) return False;
1333 /* Keep a copy so we can try decrypting it with multiple keys */
1334 buffer_copy(&st->scratch, msg0);
1336 problem = call_transform_reverse(st,st->current.transform,
1337 msg0,&transform_err);
1339 if (!st->auxiliary_is_new)
1340 delete_one_key(st,&st->auxiliary_key,
1341 "peer has used new key","auxiliary key",LOG_SEC);
1344 if (transform_apply_return_badseq(problem))
1347 buffer_copy(msg0, &st->scratch);
1348 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1351 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1352 if (st->auxiliary_is_new) {
1353 /* We previously timed out in state SENTMSG5 but it turns
1354 * out that our peer did in fact get our MSG5 and is
1355 * using the new key. So we should switch to it too. */
1356 /* This is a bit like activate_new_key. */
1359 st->current=st->auxiliary_key;
1360 st->auxiliary_key=t;
1362 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1363 "previous key",LOG_SEC);
1364 st->auxiliary_is_new=0;
1365 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1369 if (transform_apply_return_badseq(problem))
1372 if (st->state==SITE_SENTMSG5) {
1373 buffer_copy(msg0, &st->scratch);
1374 problem = call_transform_reverse(st,st->new_transform,
1377 /* It looks like we didn't get the peer's MSG6 */
1378 /* This is like a cut-down enter_new_state(SITE_RUN) */
1379 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1380 BUF_FREE(&st->buffer);
1382 activate_new_key(st);
1383 return 0; /* do process the data in this packet */
1385 if (transform_apply_return_badseq(problem))
1389 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1390 transform_err,auxkey_err,newkey_err);
1391 initiate_key_setup(st,"incoming message would not decrypt",0);
1392 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1397 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1402 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1403 const struct comm_addr *src)
1406 transform_apply_return problem;
1408 problem = decrypt_msg0(st,msg0,src);
1409 if (problem==transform_apply_seqdupe) {
1410 /* We recently received another copy of this packet, maybe due
1411 * to polypath. That's not a problem; indeed, for the
1412 * purposes of transport address management it is a success.
1413 * But we don't want to process the packet. */
1414 transport_data_msgok(st,src);
1420 CHECK_AVAIL(msg0,4);
1421 type=buf_unprepend_uint32(msg0);
1424 /* We must forget about the current session. */
1425 delete_keys(st,"request from peer",LOG_SEC);
1426 /* probably, the peer is shutting down, and this is going to fail,
1427 * but we need to be trying to bring the link up again */
1429 initiate_key_setup(st,"peer requested key teardown",0);
1432 /* Deliver to netlink layer */
1433 st->netlink->deliver(st->netlink->st,msg0);
1434 transport_data_msgok(st,src);
1435 /* See whether we should start negotiating a new key */
1436 if (st->now > st->renegotiate_key_time)
1437 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1440 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1447 static void dump_packet(struct site *st, struct buffer_if *buf,
1448 const struct comm_addr *addr, bool_t incoming,
1451 uint32_t dest=get_uint32(buf->start);
1452 uint32_t source=get_uint32(buf->start+4);
1453 uint32_t msgtype=get_uint32(buf->start+8);
1455 if (st->log_events & LOG_DUMP)
1456 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1457 st->tunname,incoming?"incoming":"outgoing",
1458 dest,source,msgtype,comm_addr_to_string(addr),
1462 static bool_t comm_addr_sendmsg(struct site *st,
1463 const struct comm_addr *dest,
1464 struct buffer_if *buf)
1467 struct comm_clientinfo *commclientinfo = 0;
1469 for (i=0; i < st->ncomms; i++) {
1470 if (st->comms[i] == dest->comm) {
1471 commclientinfo = st->commclientinfos[i];
1475 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1478 static uint32_t site_status(void *st)
1483 static bool_t send_msg(struct site *st)
1485 if (st->retries>0) {
1486 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1487 st->timeout=st->now+st->setup_retry_interval;
1490 } else if (st->state==SITE_SENTMSG5) {
1491 logtimeout(st,"timed out sending MSG5, stashing new key");
1492 /* We stash the key we have produced, in case it turns out that
1493 * our peer did see our MSG5 after all and starts using it. */
1494 /* This is a bit like some of activate_new_key */
1495 struct transform_inst_if *t;
1496 t=st->auxiliary_key.transform;
1497 st->auxiliary_key.transform=st->new_transform;
1498 st->new_transform=t;
1499 dispose_transform(&st->new_transform);
1501 st->auxiliary_is_new=1;
1502 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1503 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1504 st->auxiliary_key.remote_session_id=st->setup_session_id;
1506 enter_state_wait(st);
1509 logtimeout(st,"timed out sending key setup packet "
1510 "(in state %s)",state_name(st->state));
1511 enter_state_wait(st);
1516 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1517 int stored_naddrs, int all_naddrs,
1518 const char *address, const char *failwhy)
1520 struct site *st=sst;
1522 if (!stored_naddrs) {
1523 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1525 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1526 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1528 int space=st->transport_peers_max-st->resolving_n_results_stored;
1529 int n_tocopy=MIN(stored_naddrs,space);
1530 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1533 st->resolving_n_results_stored += n_tocopy;
1534 st->resolving_n_results_all += all_naddrs;
1537 decrement_resolving_count(st,1);
1540 static void decrement_resolving_count(struct site *st, int by)
1542 assert(st->resolving_count>0);
1543 st->resolving_count-=by;
1545 if (st->resolving_count)
1548 /* OK, we are done with them all. Handle combined results. */
1550 const struct comm_addr *addrs=st->resolving_results;
1551 int naddrs=st->resolving_n_results_stored;
1552 assert(naddrs<=st->transport_peers_max);
1555 if (naddrs != st->resolving_n_results_all) {
1556 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1557 " yielded too many results (%d > %d), some ignored",
1558 st->resolving_n_results_all, naddrs);
1560 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1561 naddrs, iaddr_to_string(&addrs[0].ia));;
1564 switch (st->state) {
1566 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1567 enter_new_state(st,SITE_SENTMSG1,0);
1569 /* Can't figure out who to try to to talk to */
1570 slog(st,LOG_SETUP_INIT,
1571 "key exchange failed: cannot find peer address");
1572 enter_state_run(st);
1575 case SITE_SENTMSG1: case SITE_SENTMSG2:
1576 case SITE_SENTMSG3: case SITE_SENTMSG4:
1579 /* We start using the address immediately for data too.
1580 * It's best to store it in st->peers now because we might
1581 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1582 * the new key (without updating the data peer addrs). */
1583 transport_resolve_complete(st,addrs,naddrs);
1584 } else if (st->local_mobile) {
1585 /* We can't let this rest because we may have a peer
1586 * address which will break in the future. */
1587 slog(st,LOG_SETUP_INIT,"resolution failed: "
1588 "abandoning key exchange");
1589 enter_state_wait(st);
1591 slog(st,LOG_SETUP_INIT,"resolution failed: "
1592 " continuing to use source address of peer's packets"
1593 " for key exchange and ultimately data");
1598 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1599 " updating peer address(es)");
1600 transport_resolve_complete_tardy(st,addrs,naddrs);
1601 } else if (st->local_mobile) {
1602 /* Not very good. We should queue (another) renegotiation
1603 * so that we can update the peer address. */
1604 st->key_renegotiate_time=st->now+wait_timeout(st);
1606 slog(st,LOG_SETUP_INIT,"resolution failed: "
1607 " continuing to use source address of peer's packets");
1617 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1618 const struct comm_addr *prod_hint)
1620 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1621 if (st->state!=SITE_RUN) return False;
1622 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1623 if (st->addresses) {
1624 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1625 return enter_state_resolve(st);
1626 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1627 return enter_new_state(st,SITE_SENTMSG1,0);
1629 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1633 static void activate_new_key(struct site *st)
1635 struct transform_inst_if *t;
1637 /* We have three transform instances, which we swap between old,
1639 t=st->auxiliary_key.transform;
1640 st->auxiliary_key.transform=st->current.transform;
1641 st->current.transform=st->new_transform;
1642 st->new_transform=t;
1643 dispose_transform(&st->new_transform);
1646 st->auxiliary_is_new=0;
1647 st->auxiliary_key.key_timeout=st->current.key_timeout;
1648 st->current.key_timeout=st->now+st->key_lifetime;
1649 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1650 transport_peers_copy(st,&st->peers,&st->setup_peers);
1651 st->current.remote_session_id=st->setup_session_id;
1653 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1654 * But their mtu be unspecified, in which case we just use ours. */
1655 uint32_t intersite_mtu=
1656 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1657 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1659 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1660 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1661 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1662 enter_state_run(st);
1665 static void delete_one_key(struct site *st, struct data_key *key,
1666 cstring_t reason, cstring_t which, uint32_t loglevel)
1668 if (!is_transform_valid(key->transform)) return;
1669 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1670 dispose_transform(&key->transform);
1674 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1676 if (current_valid(st)) {
1677 slog(st,loglevel,"session closed (%s)",reason);
1679 delete_one_key(st,&st->current,0,0,0);
1680 set_link_quality(st);
1682 delete_one_key(st,&st->auxiliary_key,0,0,0);
1685 static void state_assert(struct site *st, bool_t ok)
1687 if (!ok) fatal("site:state_assert");
1690 static void enter_state_stop(struct site *st)
1692 st->state=SITE_STOP;
1694 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1695 dispose_transform(&st->new_transform);
1698 static void set_link_quality(struct site *st)
1701 if (current_valid(st))
1702 quality=LINK_QUALITY_UP;
1703 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1704 quality=LINK_QUALITY_DOWN;
1705 else if (st->addresses)
1706 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1707 else if (transport_peers_valid(&st->peers))
1708 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1710 quality=LINK_QUALITY_DOWN;
1712 st->netlink->set_quality(st->netlink->st,quality);
1715 static void enter_state_run(struct site *st)
1717 slog(st,LOG_STATE,"entering state RUN%s",
1718 current_valid(st) ? " (keyed)" : " (unkeyed)");
1722 st->setup_session_id=0;
1723 transport_peers_clear(st,&st->setup_peers);
1724 keyset_dispose(&st->peerkeys_kex);
1725 FILLZERO(st->localN);
1726 FILLZERO(st->remoteN);
1727 dispose_transform(&st->new_transform);
1728 memset(st->dhsecret,0,st->dh->len);
1729 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1730 set_link_quality(st);
1732 if (st->keepalive && !current_valid(st))
1733 initiate_key_setup(st, "keepalive", 0);
1736 static bool_t ensure_resolving(struct site *st)
1738 /* Reentrancy hazard: may call site_resolve_callback and hence
1739 * enter_new_state, enter_state_* and generate_msg*. */
1740 if (st->resolving_count)
1743 assert(st->addresses);
1745 /* resolver->request might reentrantly call site_resolve_callback
1746 * which will decrement st->resolving, so we need to increment it
1747 * twice beforehand to prevent decrement from thinking we're
1748 * finished, and decrement it ourselves. Alternatively if
1749 * everything fails then there are no callbacks due and we simply
1750 * set it to 0 and return false.. */
1751 st->resolving_n_results_stored=0;
1752 st->resolving_n_results_all=0;
1753 st->resolving_count+=2;
1754 const char **addrp=st->addresses;
1755 const char *address;
1757 for (; (address=*addrp++); ) {
1758 bool_t ok = st->resolver->request(st->resolver->st,address,
1759 st->remoteport,st->comms[0],
1760 site_resolve_callback,st);
1762 st->resolving_count++;
1766 st->resolving_count=0;
1769 decrement_resolving_count(st,2);
1773 static bool_t enter_state_resolve(struct site *st)
1775 /* Reentrancy hazard! See ensure_resolving. */
1776 state_assert(st,st->state==SITE_RUN);
1777 slog(st,LOG_STATE,"entering state RESOLVE");
1778 st->state=SITE_RESOLVE;
1779 return ensure_resolving(st);
1782 static bool_t enter_new_state(struct site *st, uint32_t next,
1783 const struct msg *prompt
1784 /* may be 0 for SENTMSG1 */)
1786 bool_t (*gen)(struct site *st, const struct msg *prompt);
1789 slog(st,LOG_STATE,"entering state %s",state_name(next));
1792 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1793 if (!kex_init(st)) return False;
1795 st->msg1_crossed_logged = False;
1798 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1799 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1800 if (!kex_init(st)) return False;
1804 state_assert(st,st->state==SITE_SENTMSG1);
1805 BUF_FREE(&st->buffer);
1809 state_assert(st,st->state==SITE_SENTMSG2);
1810 BUF_FREE(&st->buffer);
1814 state_assert(st,st->state==SITE_SENTMSG3);
1815 BUF_FREE(&st->buffer);
1819 state_assert(st,st->state==SITE_SENTMSG4);
1820 BUF_FREE(&st->buffer);
1825 fatal("enter_new_state(%s): invalid new state",state_name(next));
1829 if (hacky_par_start_failnow()) return False;
1831 r= gen(st,prompt) && send_msg(st);
1834 st->setup_retries, st->setup_retry_interval,
1839 if (next==SITE_RUN) {
1840 BUF_FREE(&st->buffer); /* Never reused */
1841 st->timeout=0; /* Never retransmit */
1842 activate_new_key(st);
1846 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1847 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1848 in either state, and enter_state_wait() will
1850 enter_state_wait(st);
1854 /* msg7 tells our peer that we're about to forget our key */
1855 static bool_t send_msg7(struct site *st, cstring_t reason)
1857 cstring_t transform_err;
1859 if (current_valid(st) && st->buffer.free
1860 && transport_peers_valid(&st->peers)) {
1861 BUF_ALLOC(&st->buffer,"site:MSG7");
1862 buffer_init(&st->buffer,calculate_max_start_pad());
1863 buf_append_uint32(&st->buffer,LABEL_MSG7);
1864 buf_append_string(&st->buffer,reason);
1865 if (call_transform_forwards(st, st->current.transform,
1866 &st->buffer, &transform_err))
1868 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1869 buf_prepend_uint32(&st->buffer,st->index);
1870 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1871 transport_xmit(st,&st->peers,&st->buffer,True);
1872 BUF_FREE(&st->buffer);
1879 /* We go into this state if our peer becomes uncommunicative. Similar to
1880 the "stop" state, we forget all session keys for a while, before
1881 re-entering the "run" state. */
1882 static void enter_state_wait(struct site *st)
1884 slog(st,LOG_STATE,"entering state WAIT");
1885 st->timeout=st->now+wait_timeout(st);
1886 st->state=SITE_WAIT;
1887 set_link_quality(st);
1888 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1889 /* XXX Erase keys etc. */
1892 static void generate_prod(struct site *st, struct buffer_if *buf)
1895 buf_append_uint32(buf,0);
1896 buf_append_uint32(buf,0);
1897 buf_append_uint32(buf,LABEL_PROD);
1898 buf_append_string(buf,st->localname);
1899 buf_append_string(buf,st->remotename);
1902 static void generate_send_prod(struct site *st,
1903 const struct comm_addr *source)
1905 if (!st->allow_send_prod) return; /* too soon */
1906 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1907 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1909 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1910 st->allow_send_prod=0;
1911 generate_prod(st,&st->scratch);
1912 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1913 dump_packet(st,&st->scratch,source,False,ok);
1916 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1919 int64_t offset=timeout-*now;
1920 if (offset<0) offset=0;
1921 if (offset>INT_MAX) offset=INT_MAX;
1922 if (*timeout_io<0 || offset<*timeout_io)
1927 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1930 struct site *st=sst;
1932 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1935 /* Work out when our next timeout is. The earlier of 'timeout' or
1936 'current.key_timeout'. A stored value of '0' indicates no timeout
1938 site_settimeout(st->timeout, timeout_io);
1939 site_settimeout(st->current.key_timeout, timeout_io);
1940 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1942 return 0; /* success */
1945 static void check_expiry(struct site *st, struct data_key *key,
1948 if (key->key_timeout && *now>key->key_timeout) {
1949 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1953 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1954 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1956 struct site *st=sst;
1959 if (st->timeout && *now>st->timeout) {
1961 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1962 if (!hacky_par_start_failnow())
1964 } else if (st->state==SITE_WAIT) {
1965 enter_state_run(st);
1967 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1971 check_expiry(st,&st->current,"current key");
1972 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1975 /* This function is called by the netlink device to deliver packets
1976 intended for the remote network. The packet is in "raw" wire
1977 format, but is guaranteed to be word-aligned. */
1978 static void site_outgoing(void *sst, struct buffer_if *buf)
1980 struct site *st=sst;
1981 cstring_t transform_err;
1983 if (st->state==SITE_STOP) {
1988 st->allow_send_prod=1;
1990 /* In all other states we consider delivering the packet if we have
1991 a valid key and a valid address to send it to. */
1992 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1993 /* Transform it and send it */
1995 buf_prepend_uint32(buf,LABEL_MSG9);
1996 if (call_transform_forwards(st, st->current.transform,
1997 buf, &transform_err))
1999 buf_prepend_uint32(buf,LABEL_MSG0);
2000 buf_prepend_uint32(buf,st->index);
2001 buf_prepend_uint32(buf,st->current.remote_session_id);
2002 transport_xmit(st,&st->peers,buf,False);
2009 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
2011 initiate_key_setup(st,"outgoing packet",0);
2014 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
2015 uint32_t type, struct msg *m,
2016 struct priomsg *whynot)
2017 /* For packets which are identified by the local and remote names.
2018 * If it has our name and our peer's name in it it's for us. */
2020 struct buffer_if buf[1];
2021 buffer_readonly_clone(buf,buf_in);
2023 if (!unpick_msg(st,type,buf,m)) {
2024 priomsg_update_fixed(whynot, comm_notify_whynot_unpick, "malformed");
2027 #define NAME_MATCHES(lr) \
2028 if (!name_matches(&m->lr, st->lr##name)) { \
2029 if (priomsg_update_fixed(whynot, comm_notify_whynot_name_##lr, \
2030 "unknown " #lr " name: ")) { \
2031 truncmsg_add_packet_string(&whynot->m, m->lr.len, m->lr.name); \
2035 NAME_MATCHES(remote);
2036 NAME_MATCHES(local );
2042 static bool_t we_have_priority(struct site *st, const struct msg *m) {
2043 if (st->local_capabilities & m->remote_capabilities &
2044 CAPAB_PRIORITY_MOBILE) {
2045 if (st->local_mobile) return True;
2046 if (st-> peer_mobile) return False;
2048 return st->our_name_later;
2051 static bool_t setup_late_msg_ok(struct site *st,
2052 const struct buffer_if *buf_in,
2054 const struct comm_addr *source,
2055 struct msg *m /* returned */) {
2056 /* For setup packets which seem from their type like they are
2057 * late. Maybe they came via a different path. All we do is make
2058 * a note of the sending address, iff they look like they are part
2059 * of the current key setup attempt. */
2060 if (!named_for_us(st,buf_in,msgtype,m,0))
2061 /* named_for_us calls unpick_msg which gets the nonces */
2063 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
2064 !consttime_memeq(m->nL,st->localN, NONCELEN))
2065 /* spoof ? from stale run ? who knows */
2067 transport_setup_msgok(st,source);
2071 /* This function is called by the communication device to deliver
2072 packets from our peers.
2073 It should return True if the packet is recognised as being for
2074 this current site instance (and should therefore not be processed
2075 by other sites), even if the packet was otherwise ignored. */
2076 static bool_t site_incoming(void *sst, struct buffer_if *buf,
2077 const struct comm_addr *source,
2078 struct priomsg *whynot)
2080 struct site *st=sst;
2082 if (buf->size < 12) return False;
2084 uint32_t dest=get_uint32(buf->start);
2085 uint32_t msgtype=get_uint32(buf->start+8);
2087 /* initialised by named_for_us, or process_msgN for N!=1 */
2089 if (msgtype==LABEL_MSG1) {
2090 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2092 /* It's a MSG1 addressed to us. Decide what to do about it. */
2093 dump_packet(st,buf,source,True,True);
2094 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
2095 st->state==SITE_WAIT) {
2096 /* We should definitely process it */
2097 transport_compute_setupinit_peers(st,0,0,source);
2098 if (process_msg1(st,buf,source,&msg)) {
2099 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
2100 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
2101 if (entered && st->addresses && st->local_mobile)
2102 /* We must do this as the very last thing, because
2103 the resolver callback might reenter us. */
2104 ensure_resolving(st);
2106 slog(st,LOG_ERROR,"failed to process incoming msg1");
2110 } else if (st->state==SITE_SENTMSG1) {
2111 /* We've just sent a message 1! They may have crossed on
2112 the wire. If we have priority then we ignore the
2113 incoming one, otherwise we process it as usual. */
2114 if (we_have_priority(st,&msg)) {
2116 if (!st->msg1_crossed_logged++)
2117 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
2118 "priority => ignore incoming msg1");
2121 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
2122 "priority => use incoming msg1");
2123 if (process_msg1(st,buf,source,&msg)) {
2124 BUF_FREE(&st->buffer); /* Free our old message 1 */
2125 transport_setup_msgok(st,source);
2126 enter_new_state(st,SITE_SENTMSG2,&msg);
2128 slog(st,LOG_ERROR,"failed to process an incoming "
2129 "crossed msg1 (we have low priority)");
2134 } else if (st->state==SITE_SENTMSG2 ||
2135 st->state==SITE_SENTMSG4) {
2136 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
2137 /* We are ahead in the protocol, but that msg1 had the
2138 * peer's nonce so presumably it is from this key
2139 * exchange run, via a slower route */
2140 transport_setup_msgok(st,source);
2142 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
2147 /* The message 1 was received at an unexpected stage of the
2148 key setup. Well, they lost the race. */
2149 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
2153 if (msgtype==LABEL_PROD) {
2154 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2156 dump_packet(st,buf,source,True,True);
2157 if (st->state!=SITE_RUN) {
2158 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
2159 } else if (current_valid(st)) {
2160 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
2162 initiate_key_setup(st,"peer sent PROD packet",source);
2167 if (dest==st->index) {
2168 /* Explicitly addressed to us */
2169 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
2172 /* If the source is our current peer then initiate a key setup,
2173 because our peer's forgotten the key */
2174 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
2176 initiated = initiate_key_setup(st,"received a NAK",source);
2177 if (!initiated) generate_send_prod(st,source);
2179 slog(st,LOG_SEC,"bad incoming NAK");
2183 process_msg0(st,buf,source);
2186 /* Setup packet: should not have been explicitly addressed
2188 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2191 /* Setup packet: expected only in state SENTMSG1 */
2192 if (st->state!=SITE_SENTMSG1) {
2193 if ((st->state==SITE_SENTMSG3 ||
2194 st->state==SITE_SENTMSG5) &&
2195 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2197 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
2198 } else if (process_msg2(st,buf,source,&msg)) {
2199 transport_setup_msgok(st,source);
2200 enter_new_state(st,SITE_SENTMSG3,&msg);
2202 slog(st,LOG_SEC,"invalid MSG2");
2205 case CASES_MSG3_KNOWN:
2206 /* Setup packet: expected only in state SENTMSG2 */
2207 if (st->state!=SITE_SENTMSG2) {
2208 if ((st->state==SITE_SENTMSG4) &&
2209 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2211 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2212 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2213 transport_setup_msgok(st,source);
2214 enter_new_state(st,SITE_SENTMSG4,&msg);
2216 slog(st,LOG_SEC,"invalid MSG3");
2220 /* Setup packet: expected only in state SENTMSG3 */
2221 if (st->state!=SITE_SENTMSG3) {
2222 if ((st->state==SITE_SENTMSG5) &&
2223 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2225 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2226 } else if (process_msg4(st,buf,source,&msg)) {
2227 transport_setup_msgok(st,source);
2228 enter_new_state(st,SITE_SENTMSG5,&msg);
2230 slog(st,LOG_SEC,"invalid MSG4");
2234 /* Setup packet: expected only in state SENTMSG4 */
2235 /* (may turn up in state RUN if our return MSG6 was lost
2236 and the new key has already been activated. In that
2237 case we discard it. The peer will realise that we
2238 are using the new key when they see our data packets.
2239 Until then the peer's data packets to us get discarded. */
2240 if (st->state==SITE_SENTMSG4) {
2241 if (process_msg5(st,buf,source,st->new_transform)) {
2242 transport_setup_msgok(st,source);
2243 enter_new_state(st,SITE_RUN,&msg);
2245 slog(st,LOG_SEC,"invalid MSG5");
2247 } else if (st->state==SITE_RUN) {
2248 if (process_msg5(st,buf,source,st->current.transform)) {
2249 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2250 transport_setup_msgok(st,source);
2251 create_msg6(st,st->current.transform,
2252 st->current.remote_session_id);
2253 transport_xmit(st,&st->peers,&st->buffer,True);
2254 BUF_FREE(&st->buffer);
2256 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2259 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2263 /* Setup packet: expected only in state SENTMSG5 */
2264 if (st->state!=SITE_SENTMSG5) {
2265 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2266 } else if (process_msg6(st,buf,source)) {
2267 BUF_FREE(&st->buffer); /* Free message 5 */
2268 transport_setup_msgok(st,source);
2269 activate_new_key(st);
2271 slog(st,LOG_SEC,"invalid MSG6");
2275 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2283 priomsg_update_fixed(whynot, comm_notify_whynot_general,
2284 "not MSG1 or PROD; unknown dest index");
2288 static void site_control(void *vst, bool_t run)
2290 struct site *st=vst;
2291 if (run) enter_state_run(st);
2292 else enter_state_stop(st);
2295 static void site_phase_hook(void *sst, uint32_t newphase)
2297 struct site *st=sst;
2299 /* The program is shutting down; tell our peer */
2300 send_msg7(st,"shutting down");
2303 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2305 struct site *st=sst;
2306 dispose_transform(&st->current.transform);
2307 dispose_transform(&st->auxiliary_key.transform);
2308 dispose_transform(&st->new_transform);
2309 /* Not much point overwiting the signing key, since we loaded it
2310 from disk, and it is only valid prospectively if at all,
2312 /* XXX it would be best to overwrite the DH state, because that
2313 _is_ relevant to forward secrecy. However we have no
2314 convenient interface for doing that and in practice gmp has
2315 probably dribbled droppings all over the malloc arena. A good
2316 way to fix this would be to have a privsep child for asymmetric
2317 crypto operations, but that's a task for another day. */
2320 static void setup_sethash(struct site *st, dict_t *dict,
2322 sig_sethash_fn *sethash, void *sigkey_st) {
2324 cfgfatal(loc,"site","other settings imply `hash' key is needed");
2325 sethash(sigkey_st,st->defhash);
2327 #define SETUP_SETHASH(k) do{ \
2329 setup_sethash(st,dict,loc, (k)->sethash,(k)->st); \
2332 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2335 static uint32_t index_sequence;
2343 st->cl.description="site";
2344 st->cl.type=CL_SITE;
2346 st->cl.interface=&st->ops;
2348 st->ops.control=site_control;
2349 st->ops.status=site_status;
2350 st->peerkeys_path=0;
2351 st->peerkeys_tmpl.buffer=0;
2352 st->peerkeys_current=st->peerkeys_kex=0;
2354 /* First parameter must be a dict */
2355 item=list_elem(args,0);
2356 if (!item || item->type!=t_dict)
2357 cfgfatal(loc,"site","parameter must be a dictionary\n");
2359 dict=item->data.dict;
2360 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2361 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2363 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2365 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2367 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2369 /* Sanity check (which also allows the 'sites' file to include
2370 site() closures for all sites including our own): refuse to
2371 talk to ourselves */
2372 if (strcmp(st->localname,st->remotename)==0) {
2373 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2375 if (st->peer_mobile != st->local_mobile)
2376 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2377 " but our local-mobile=%d\n",
2378 st->localname, st->peer_mobile, st->local_mobile);
2382 if (st->peer_mobile && st->local_mobile) {
2383 Message(M_WARNING,"site %s: site is mobile but so are we"
2384 " -> ignoring this site\n", st->remotename);
2389 assert(index_sequence < 0xffffffffUL);
2390 st->index = ++index_sequence;
2391 st->local_capabilities = 0;
2392 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2393 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2395 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2396 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2397 if (!things##_cfg) \
2398 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2399 st->nthings=list_length(things##_cfg); \
2400 NEW_ARY(st->things,st->nthings); \
2401 assert(st->nthings); \
2402 for (i=0; i<st->nthings; i++) { \
2403 item_t *item=list_elem(things##_cfg,i); \
2404 if (item->type!=t_closure) \
2405 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2406 closure_t *cl=item->data.closure; \
2407 if (cl->type!=CL_TYPE) \
2408 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2409 st->things[i]=cl->interface; \
2413 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2415 NEW_ARY(st->commclientinfos, st->ncomms);
2416 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2417 for (i=0; i<st->ncomms; i++) {
2418 st->commclientinfos[i] =
2420 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2423 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2424 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2425 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2427 st->defhash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2429 st->privkeys=find_cl_if(dict,"key-cache",CL_PRIVCACHE,False,"site",loc);
2430 if (!st->privkeys) {
2432 find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2433 SETUP_SETHASH(st->privkey_fixed);
2436 struct sigpubkey_if *fixed_pubkey
2437 =find_cl_if(dict,"key",CL_SIGPUBKEY,False,"site",loc);
2438 st->peerkeys_path=dict_read_string(dict,"peer-keys",fixed_pubkey==0,
2440 if (st->peerkeys_path) {
2441 pathprefix_template_init(&st->peerkeys_tmpl,st->peerkeys_path,
2442 PEERKEYS_SUFFIX_MAXLEN + 1 /* nul */);
2443 st->peerkeys_current=keyset_load(st->peerkeys_path,
2444 &st->scratch,st->log,M_ERR,
2447 fixed_pubkey->dispose(fixed_pubkey->st);
2450 assert(fixed_pubkey);
2451 SETUP_SETHASH(fixed_pubkey);
2452 NEW(st->peerkeys_current);
2453 st->peerkeys_current->refcount=1;
2454 st->peerkeys_current->nkeys=1;
2455 st->peerkeys_current->keys[0].id=keyid_zero;
2456 st->peerkeys_current->keys[0].pubkey=fixed_pubkey;
2457 slog(st,LOG_SIGKEYS,
2458 "using old-style fixed peer public key (no `peer-keys')");
2461 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2463 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2464 else st->remoteport=0;
2466 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2468 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2470 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2471 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2472 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2474 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2475 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2476 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2477 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2478 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2480 st->mobile_peer_expiry= dict_read_number(
2481 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2483 const char *peerskey= st->peer_mobile
2484 ? "mobile-peers-max" : "static-peers-max";
2485 st->transport_peers_max= dict_read_number(
2486 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2487 if (st->transport_peers_max<1 ||
2488 st->transport_peers_max>MAX_PEER_ADDRS) {
2489 cfgfatal(loc,"site", "%s must be in range 1.."
2490 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2493 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2494 st->key_renegotiate_time=st->key_lifetime/2;
2496 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2497 st->key_renegotiate_time=dict_read_number(
2498 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2499 if (st->key_renegotiate_time > st->key_lifetime) {
2500 cfgfatal(loc,"site",
2501 "renegotiate-time must be less than key-lifetime\n");
2504 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2505 log_event_table,"site");
2507 st->resolving_count=0;
2508 st->allow_send_prod=0;
2510 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2512 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2514 /* The information we expect to see in incoming messages of type 1 */
2515 /* fixme: lots of unchecked overflows here, but the results are only
2516 corrupted packets rather than undefined behaviour */
2517 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2519 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2521 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2522 BUF_ALLOC(&st->scratch,"site:scratch");
2524 /* We are interested in poll(), but only for timeouts. We don't have
2525 any fds of our own. */
2526 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2529 st->remote_capabilities=0;
2530 st->chosen_transform=0;
2531 st->current.key_timeout=0;
2532 st->auxiliary_key.key_timeout=0;
2533 transport_peers_clear(st,&st->peers);
2534 transport_peers_clear(st,&st->setup_peers);
2535 /* XXX mlock these */
2536 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2537 st->sharedsecretlen=st->sharedsecretallocd=0;
2540 #define SET_CAPBIT(bit) do { \
2541 uint32_t capflag = 1UL << (bit); \
2542 if (st->local_capabilities & capflag) \
2543 slog(st,LOG_ERROR,"capability bit" \
2544 " %d (%#"PRIx32") reused", (bit), capflag); \
2545 st->local_capabilities |= capflag; \
2548 for (i=0; i<st->ntransforms; i++)
2549 SET_CAPBIT(st->transforms[i]->capab_bit);
2553 if (st->local_mobile || st->peer_mobile)
2554 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2556 /* We need to register the remote networks with the netlink device */
2557 uint32_t netlink_mtu; /* local virtual interface mtu */
2558 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2559 if (!st->mtu_target)
2560 st->mtu_target=netlink_mtu;
2562 for (i=0; i<st->ncomms; i++)
2563 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2565 st->current.transform=0;
2566 st->auxiliary_key.transform=0;
2567 st->new_transform=0;
2568 st->auxiliary_is_new=0;
2570 enter_state_stop(st);
2572 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2573 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2575 return new_closure(&st->cl);
2578 void site_module(dict_t *dict)
2580 add_closure(dict,"site",site_apply);
2584 /***** TRANSPORT PEERS definitions *****/
2586 static void transport_peers_debug(struct site *st, transport_peers *dst,
2587 const char *didwhat,
2588 int nargs, const struct comm_addr *args,
2593 if (!(st->log_events & LOG_PEER_ADDRS))
2594 return; /* an optimisation */
2596 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2597 (dst==&st->peers ? "data" :
2598 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2599 didwhat, nargs, dst->npeers);
2601 for (i=0, argp=(void*)args;
2603 i++, (argp+=stride?stride:sizeof(*args))) {
2604 const struct comm_addr *ca=(void*)argp;
2605 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2606 i, comm_addr_to_string(ca));
2608 for (i=0; i<dst->npeers; i++) {
2609 struct timeval diff;
2610 timersub(tv_now,&dst->peers[i].last,&diff);
2611 const struct comm_addr *ca=&dst->peers[i].addr;
2612 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2613 i, comm_addr_to_string(ca),
2614 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2618 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2619 /* peers must be sorted first */
2620 int previous_peers=peers->npeers;
2621 struct timeval oldest;
2622 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2623 oldest.tv_usec = tv_now->tv_usec;
2624 while (peers->npeers>1 &&
2625 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2627 if (peers->npeers != previous_peers)
2628 transport_peers_debug(st,peers,"expire", 0,0,0);
2631 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2632 const struct comm_addr *ca,
2633 const struct timeval *tv) {
2634 /* returns false if output is full */
2637 if (peers->npeers >= st->transport_peers_max)
2640 for (search=0; search<peers->npeers; search++)
2641 if (comm_addr_equal(&peers->peers[search].addr, ca))
2644 peers->peers[peers->npeers].addr = *ca;
2645 peers->peers[peers->npeers].last = *tv;
2650 static void transport_record_peers(struct site *st, transport_peers *peers,
2651 const struct comm_addr *addrs, int naddrs,
2653 /* We add addrs into peers. The new entries end up at the front
2654 * and displace entries towards the end (perhaps even off the
2655 * end). Any existing matching entries are moved up to the front.
2657 * Caller must first call transport_peers_expire. */
2660 /* avoids debug for uninteresting updates */
2662 for (i=0; i<peers->npeers; i++) {
2663 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2664 memmove(peers->peers+1, peers->peers,
2665 sizeof(peers->peers[0]) * i);
2666 peers->peers[0].addr = addrs[0];
2667 peers->peers[0].last = *tv_now;
2673 int old_npeers=peers->npeers;
2674 transport_peer old_peers[old_npeers];
2675 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2679 for (i=0; i<naddrs; i++) {
2680 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2683 for (i=0; i<old_npeers; i++) {
2684 const transport_peer *old=&old_peers[i];
2685 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2689 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2692 static void transport_expire_record_peers(struct site *st,
2693 transport_peers *peers,
2694 const struct comm_addr *addrs,
2695 int naddrs, const char *m) {
2696 /* Convenience function */
2697 transport_peers_expire(st,peers);
2698 transport_record_peers(st,peers,addrs,naddrs,m);
2701 static bool_t transport_compute_setupinit_peers(struct site *st,
2702 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2703 int n_configured_addrs /* 0 if none or not found */,
2704 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2705 if (!n_configured_addrs && !incoming_packet_addr &&
2706 !transport_peers_valid(&st->peers))
2709 slog(st,LOG_SETUP_INIT,
2710 "using: %d configured addr(s);%s %d old peer addrs(es)",
2712 incoming_packet_addr ? " incoming packet address;" : "",
2715 /* Non-mobile peers try addresses until one is plausible. The
2716 * effect is that this code always tries first the configured
2717 * address if supplied, or otherwise the address of the incoming
2718 * PROD, or finally the existing data peer if one exists; this is
2721 transport_peers_copy(st,&st->setup_peers,&st->peers);
2722 transport_peers_expire(st,&st->setup_peers);
2724 if (incoming_packet_addr)
2725 transport_record_peers(st,&st->setup_peers,
2726 incoming_packet_addr,1, "incoming");
2728 if (n_configured_addrs)
2729 transport_record_peers(st,&st->setup_peers,
2730 configured_addrs,n_configured_addrs, "setupinit");
2732 assert(transport_peers_valid(&st->setup_peers));
2736 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2737 if (st->peer_mobile)
2738 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2740 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2741 if (st->peer_mobile)
2742 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2745 static int transport_peers_valid(transport_peers *peers) {
2746 return peers->npeers;
2748 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2750 transport_peers_debug(st,peers,"clear",0,0,0);
2752 static void transport_peers_copy(struct site *st, transport_peers *dst,
2753 const transport_peers *src) {
2754 dst->npeers=src->npeers;
2755 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2756 transport_peers_debug(st,dst,"copy",
2757 src->npeers, &src->peers->addr, sizeof(*src->peers));
2760 static void transport_resolve_complete(struct site *st,
2761 const struct comm_addr *addrs,
2763 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2765 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2769 static void transport_resolve_complete_tardy(struct site *st,
2770 const struct comm_addr *addrs,
2772 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2773 "resolved tardily");
2776 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2778 const transport_peers *inp) {
2779 /* out and in->peers may be the same region, or nonoverlapping */
2780 const transport_peer *in=inp->peers;
2782 for (slot=0; slot<inp->npeers; slot++) {
2783 if (!(mask & (1U << slot)))
2785 if (!(out==in && slot==*nout_io))
2786 COPY_OBJ(out[*nout_io], in[slot]);
2791 void transport_xmit(struct site *st, transport_peers *peers,
2792 struct buffer_if *buf, bool_t candebug) {
2794 transport_peers_expire(st, peers);
2795 unsigned failed=0; /* bitmask */
2796 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2799 for (slot=0; slot<peers->npeers; slot++) {
2800 transport_peer *peer=&peers->peers[slot];
2801 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2803 dump_packet(st, buf, &peer->addr, False, ok);
2805 failed |= 1U << slot;
2808 if (ok && !st->peer_mobile)
2811 /* Now we need to demote/delete failing addrs: if we are mobile we
2812 * merely demote them; otherwise we delete them. */
2813 if (st->local_mobile) {
2814 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2815 /* `expected' has all the failures at the end already */
2816 if (failed != expected) {
2818 transport_peer failedpeers[nfailed];
2819 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2820 assert(fslot == nfailed);
2822 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2823 assert(wslot+nfailed == peers->npeers);
2824 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2825 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2828 if (failed && peers->npeers > 1) {
2830 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2831 peers->npeers=wslot;
2832 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2837 /***** END of transport peers declarations *****/