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 #%d " SIGKEYID_PR_FMT,
715 ki, 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 #%d " SIGKEYID_PR_FMT ")",
1095 ki, SIGKEYID_PR_VAL(&st->peerkeys_kex->keys[ki].id));
1098 slog(st,LOG_SIGKEYS,"verified peer signature with key #%d "
1099 SIGKEYID_PR_FMT, ki,
1100 SIGKEYID_PR_VAL(&st->peerkeys_kex->keys[ki].id));
1102 st->remote_adv_mtu=m->remote_mtu;
1107 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
1108 const struct comm_addr *src, uint32_t msgtype,
1109 struct msg *m /* returned */)
1114 case CASES_MSG3_KNOWN: break;
1118 if (!unpick_msg(st,msgtype,msg3,m)) return False;
1119 if (!check_msg(st,msgtype,m,&err)) {
1120 slog(st,LOG_SEC,"msg3: %s",err);
1123 uint32_t capab_adv_late = m->remote_capabilities
1124 & ~st->remote_capabilities & st->early_capabilities;
1125 if (capab_adv_late) {
1126 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
1127 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
1128 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
1132 #define CHOSE_CRYPTO(kind, what) do { \
1133 struct kind##_if *iface; \
1135 for (i=0; i<st->n##kind##s; i++) { \
1136 iface=st->kind##s[i]; \
1137 if (iface->capab_bit == m->capab_##kind##num) \
1138 goto kind##_found; \
1140 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
1141 m->capab_##kind##num); \
1144 st->chosen_##kind=iface; \
1147 CHOSE_CRYPTO(transform, "transform");
1151 if (!process_msg3_msg4(st,m))
1154 /* Update our idea of the remote site's capabilities, now that we've
1155 * verified that its message was authentic.
1157 * Our previous idea of the remote site's capabilities came from the
1158 * unauthenticated MSG1. We've already checked that this new message
1159 * doesn't change any of the bits we relied upon in the past, but it may
1160 * also have set additional capability bits. We simply throw those away
1161 * now, and use the authentic capabilities from this MSG3. */
1162 st->remote_capabilities=m->remote_capabilities;
1164 /* Terminate their DH public key with a '0' */
1166 /* Invent our DH secret key */
1167 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1169 /* Generate the shared key and set up the transform */
1170 if (!set_new_transform(st,m->pk)) return False;
1175 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
1177 /* We have both nonces, their public key and our private key. Generate
1178 our public key, sign it and send it to them. */
1179 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
1182 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
1183 const struct comm_addr *src,
1184 struct msg *m /* returned */)
1188 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
1189 if (!check_msg(st,LABEL_MSG4,m,&err)) {
1190 slog(st,LOG_SEC,"msg4: %s",err);
1194 if (!process_msg3_msg4(st,m))
1197 /* Terminate their DH public key with a '0' */
1200 /* Generate the shared key and set up the transform */
1201 if (!set_new_transform(st,m->pk)) return False;
1212 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1215 CHECK_AVAIL(msg0,4);
1216 m->dest=buf_unprepend_uint32(msg0);
1217 CHECK_AVAIL(msg0,4);
1218 m->source=buf_unprepend_uint32(msg0);
1219 CHECK_AVAIL(msg0,4);
1220 m->type=buf_unprepend_uint32(msg0);
1222 /* Leaves transformed part of buffer untouched */
1225 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1227 cstring_t transform_err;
1229 BUF_ALLOC(&st->buffer,"site:MSG5");
1230 /* We are going to add four words to the message */
1231 buffer_init(&st->buffer,calculate_max_start_pad());
1232 /* Give the netlink code an opportunity to put its own stuff in the
1233 message (configuration information, etc.) */
1234 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1235 if (call_transform_forwards(st,st->new_transform,
1236 &st->buffer,&transform_err))
1238 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1239 buf_prepend_uint32(&st->buffer,st->index);
1240 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1242 st->retries=st->setup_retries;
1246 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1247 const struct comm_addr *src,
1248 struct transform_inst_if *transform)
1251 cstring_t transform_err;
1253 if (!unpick_msg0(st,msg5,&m)) return False;
1255 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1256 /* There's a problem */
1257 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1260 /* Buffer should now contain untransformed PING packet data */
1261 CHECK_AVAIL(msg5,4);
1262 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1263 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1266 /* Older versions of secnet used to write some config data here
1267 * which we ignore. So we don't CHECK_EMPTY */
1271 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1272 uint32_t session_id)
1274 cstring_t transform_err;
1276 BUF_ALLOC(&st->buffer,"site:MSG6");
1277 /* We are going to add four words to the message */
1278 buffer_init(&st->buffer,calculate_max_start_pad());
1279 /* Give the netlink code an opportunity to put its own stuff in the
1280 message (configuration information, etc.) */
1281 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1282 transform_apply_return problem =
1283 call_transform_forwards(st,transform,
1284 &st->buffer,&transform_err);
1286 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1287 buf_prepend_uint32(&st->buffer,st->index);
1288 buf_prepend_uint32(&st->buffer,session_id);
1291 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1293 if (!is_transform_valid(st->new_transform))
1295 create_msg6(st,st->new_transform,st->setup_session_id);
1296 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1300 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1301 const struct comm_addr *src)
1304 cstring_t transform_err;
1306 if (!unpick_msg0(st,msg6,&m)) return False;
1308 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1309 /* There's a problem */
1310 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1313 /* Buffer should now contain untransformed PING packet data */
1314 CHECK_AVAIL(msg6,4);
1315 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1316 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1319 /* Older versions of secnet used to write some config data here
1320 * which we ignore. So we don't CHECK_EMPTY */
1324 static transform_apply_return
1325 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1326 const struct comm_addr *src)
1328 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1330 transform_apply_return problem;
1332 if (!unpick_msg0(st,msg0,&m)) return False;
1334 /* Keep a copy so we can try decrypting it with multiple keys */
1335 buffer_copy(&st->scratch, msg0);
1337 problem = call_transform_reverse(st,st->current.transform,
1338 msg0,&transform_err);
1340 if (!st->auxiliary_is_new)
1341 delete_one_key(st,&st->auxiliary_key,
1342 "peer has used new key","auxiliary key",LOG_SEC);
1345 if (transform_apply_return_badseq(problem))
1348 buffer_copy(msg0, &st->scratch);
1349 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1352 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1353 if (st->auxiliary_is_new) {
1354 /* We previously timed out in state SENTMSG5 but it turns
1355 * out that our peer did in fact get our MSG5 and is
1356 * using the new key. So we should switch to it too. */
1357 /* This is a bit like activate_new_key. */
1360 st->current=st->auxiliary_key;
1361 st->auxiliary_key=t;
1363 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1364 "previous key",LOG_SEC);
1365 st->auxiliary_is_new=0;
1366 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1370 if (transform_apply_return_badseq(problem))
1373 if (st->state==SITE_SENTMSG5) {
1374 buffer_copy(msg0, &st->scratch);
1375 problem = call_transform_reverse(st,st->new_transform,
1378 /* It looks like we didn't get the peer's MSG6 */
1379 /* This is like a cut-down enter_new_state(SITE_RUN) */
1380 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1381 BUF_FREE(&st->buffer);
1383 activate_new_key(st);
1384 return 0; /* do process the data in this packet */
1386 if (transform_apply_return_badseq(problem))
1390 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1391 transform_err,auxkey_err,newkey_err);
1392 initiate_key_setup(st,"incoming message would not decrypt",0);
1393 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1398 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1403 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1404 const struct comm_addr *src)
1407 transform_apply_return problem;
1409 problem = decrypt_msg0(st,msg0,src);
1410 if (problem==transform_apply_seqdupe) {
1411 /* We recently received another copy of this packet, maybe due
1412 * to polypath. That's not a problem; indeed, for the
1413 * purposes of transport address management it is a success.
1414 * But we don't want to process the packet. */
1415 transport_data_msgok(st,src);
1421 CHECK_AVAIL(msg0,4);
1422 type=buf_unprepend_uint32(msg0);
1425 /* We must forget about the current session. */
1426 delete_keys(st,"request from peer",LOG_SEC);
1427 /* probably, the peer is shutting down, and this is going to fail,
1428 * but we need to be trying to bring the link up again */
1430 initiate_key_setup(st,"peer requested key teardown",0);
1433 /* Deliver to netlink layer */
1434 st->netlink->deliver(st->netlink->st,msg0);
1435 transport_data_msgok(st,src);
1436 /* See whether we should start negotiating a new key */
1437 if (st->now > st->renegotiate_key_time)
1438 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1441 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1448 static void dump_packet(struct site *st, struct buffer_if *buf,
1449 const struct comm_addr *addr, bool_t incoming,
1452 uint32_t dest=get_uint32(buf->start);
1453 uint32_t source=get_uint32(buf->start+4);
1454 uint32_t msgtype=get_uint32(buf->start+8);
1456 if (st->log_events & LOG_DUMP)
1457 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1458 st->tunname,incoming?"incoming":"outgoing",
1459 dest,source,msgtype,comm_addr_to_string(addr),
1463 static bool_t comm_addr_sendmsg(struct site *st,
1464 const struct comm_addr *dest,
1465 struct buffer_if *buf)
1468 struct comm_clientinfo *commclientinfo = 0;
1470 for (i=0; i < st->ncomms; i++) {
1471 if (st->comms[i] == dest->comm) {
1472 commclientinfo = st->commclientinfos[i];
1476 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1479 static uint32_t site_status(void *st)
1484 static bool_t send_msg(struct site *st)
1486 if (st->retries>0) {
1487 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1488 st->timeout=st->now+st->setup_retry_interval;
1491 } else if (st->state==SITE_SENTMSG5) {
1492 logtimeout(st,"timed out sending MSG5, stashing new key");
1493 /* We stash the key we have produced, in case it turns out that
1494 * our peer did see our MSG5 after all and starts using it. */
1495 /* This is a bit like some of activate_new_key */
1496 struct transform_inst_if *t;
1497 t=st->auxiliary_key.transform;
1498 st->auxiliary_key.transform=st->new_transform;
1499 st->new_transform=t;
1500 dispose_transform(&st->new_transform);
1502 st->auxiliary_is_new=1;
1503 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1504 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1505 st->auxiliary_key.remote_session_id=st->setup_session_id;
1507 enter_state_wait(st);
1510 logtimeout(st,"timed out sending key setup packet "
1511 "(in state %s)",state_name(st->state));
1512 enter_state_wait(st);
1517 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1518 int stored_naddrs, int all_naddrs,
1519 const char *address, const char *failwhy)
1521 struct site *st=sst;
1523 if (!stored_naddrs) {
1524 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1526 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1527 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1529 int space=st->transport_peers_max-st->resolving_n_results_stored;
1530 int n_tocopy=MIN(stored_naddrs,space);
1531 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1534 st->resolving_n_results_stored += n_tocopy;
1535 st->resolving_n_results_all += all_naddrs;
1538 decrement_resolving_count(st,1);
1541 static void decrement_resolving_count(struct site *st, int by)
1543 assert(st->resolving_count>0);
1544 st->resolving_count-=by;
1546 if (st->resolving_count)
1549 /* OK, we are done with them all. Handle combined results. */
1551 const struct comm_addr *addrs=st->resolving_results;
1552 int naddrs=st->resolving_n_results_stored;
1553 assert(naddrs<=st->transport_peers_max);
1556 if (naddrs != st->resolving_n_results_all) {
1557 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1558 " yielded too many results (%d > %d), some ignored",
1559 st->resolving_n_results_all, naddrs);
1561 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1562 naddrs, iaddr_to_string(&addrs[0].ia));;
1565 switch (st->state) {
1567 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1568 enter_new_state(st,SITE_SENTMSG1,0);
1570 /* Can't figure out who to try to to talk to */
1571 slog(st,LOG_SETUP_INIT,
1572 "key exchange failed: cannot find peer address");
1573 enter_state_run(st);
1576 case SITE_SENTMSG1: case SITE_SENTMSG2:
1577 case SITE_SENTMSG3: case SITE_SENTMSG4:
1580 /* We start using the address immediately for data too.
1581 * It's best to store it in st->peers now because we might
1582 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1583 * the new key (without updating the data peer addrs). */
1584 transport_resolve_complete(st,addrs,naddrs);
1585 } else if (st->local_mobile) {
1586 /* We can't let this rest because we may have a peer
1587 * address which will break in the future. */
1588 slog(st,LOG_SETUP_INIT,"resolution failed: "
1589 "abandoning key exchange");
1590 enter_state_wait(st);
1592 slog(st,LOG_SETUP_INIT,"resolution failed: "
1593 " continuing to use source address of peer's packets"
1594 " for key exchange and ultimately data");
1599 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1600 " updating peer address(es)");
1601 transport_resolve_complete_tardy(st,addrs,naddrs);
1602 } else if (st->local_mobile) {
1603 /* Not very good. We should queue (another) renegotiation
1604 * so that we can update the peer address. */
1605 st->key_renegotiate_time=st->now+wait_timeout(st);
1607 slog(st,LOG_SETUP_INIT,"resolution failed: "
1608 " continuing to use source address of peer's packets");
1618 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1619 const struct comm_addr *prod_hint)
1621 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1622 if (st->state!=SITE_RUN) return False;
1623 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1624 if (st->addresses) {
1625 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1626 return enter_state_resolve(st);
1627 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1628 return enter_new_state(st,SITE_SENTMSG1,0);
1630 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1634 static void activate_new_key(struct site *st)
1636 struct transform_inst_if *t;
1638 /* We have three transform instances, which we swap between old,
1640 t=st->auxiliary_key.transform;
1641 st->auxiliary_key.transform=st->current.transform;
1642 st->current.transform=st->new_transform;
1643 st->new_transform=t;
1644 dispose_transform(&st->new_transform);
1647 st->auxiliary_is_new=0;
1648 st->auxiliary_key.key_timeout=st->current.key_timeout;
1649 st->current.key_timeout=st->now+st->key_lifetime;
1650 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1651 transport_peers_copy(st,&st->peers,&st->setup_peers);
1652 st->current.remote_session_id=st->setup_session_id;
1654 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1655 * But their mtu be unspecified, in which case we just use ours. */
1656 uint32_t intersite_mtu=
1657 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1658 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1660 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1661 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1662 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1663 enter_state_run(st);
1666 static void delete_one_key(struct site *st, struct data_key *key,
1667 cstring_t reason, cstring_t which, uint32_t loglevel)
1669 if (!is_transform_valid(key->transform)) return;
1670 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1671 dispose_transform(&key->transform);
1675 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1677 if (current_valid(st)) {
1678 slog(st,loglevel,"session closed (%s)",reason);
1680 delete_one_key(st,&st->current,0,0,0);
1681 set_link_quality(st);
1683 delete_one_key(st,&st->auxiliary_key,0,0,0);
1686 static void state_assert(struct site *st, bool_t ok)
1688 if (!ok) fatal("site:state_assert");
1691 static void enter_state_stop(struct site *st)
1693 st->state=SITE_STOP;
1695 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1696 dispose_transform(&st->new_transform);
1699 static void set_link_quality(struct site *st)
1702 if (current_valid(st))
1703 quality=LINK_QUALITY_UP;
1704 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1705 quality=LINK_QUALITY_DOWN;
1706 else if (st->addresses)
1707 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1708 else if (transport_peers_valid(&st->peers))
1709 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1711 quality=LINK_QUALITY_DOWN;
1713 st->netlink->set_quality(st->netlink->st,quality);
1716 static void enter_state_run(struct site *st)
1718 slog(st,LOG_STATE,"entering state RUN%s",
1719 current_valid(st) ? " (keyed)" : " (unkeyed)");
1723 st->setup_session_id=0;
1724 transport_peers_clear(st,&st->setup_peers);
1725 keyset_dispose(&st->peerkeys_kex);
1726 FILLZERO(st->localN);
1727 FILLZERO(st->remoteN);
1728 dispose_transform(&st->new_transform);
1729 memset(st->dhsecret,0,st->dh->len);
1730 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1731 set_link_quality(st);
1733 if (st->keepalive && !current_valid(st))
1734 initiate_key_setup(st, "keepalive", 0);
1737 static bool_t ensure_resolving(struct site *st)
1739 /* Reentrancy hazard: may call site_resolve_callback and hence
1740 * enter_new_state, enter_state_* and generate_msg*. */
1741 if (st->resolving_count)
1744 assert(st->addresses);
1746 /* resolver->request might reentrantly call site_resolve_callback
1747 * which will decrement st->resolving, so we need to increment it
1748 * twice beforehand to prevent decrement from thinking we're
1749 * finished, and decrement it ourselves. Alternatively if
1750 * everything fails then there are no callbacks due and we simply
1751 * set it to 0 and return false.. */
1752 st->resolving_n_results_stored=0;
1753 st->resolving_n_results_all=0;
1754 st->resolving_count+=2;
1755 const char **addrp=st->addresses;
1756 const char *address;
1758 for (; (address=*addrp++); ) {
1759 bool_t ok = st->resolver->request(st->resolver->st,address,
1760 st->remoteport,st->comms[0],
1761 site_resolve_callback,st);
1763 st->resolving_count++;
1767 st->resolving_count=0;
1770 decrement_resolving_count(st,2);
1774 static bool_t enter_state_resolve(struct site *st)
1776 /* Reentrancy hazard! See ensure_resolving. */
1777 state_assert(st,st->state==SITE_RUN);
1778 slog(st,LOG_STATE,"entering state RESOLVE");
1779 st->state=SITE_RESOLVE;
1780 return ensure_resolving(st);
1783 static bool_t enter_new_state(struct site *st, uint32_t next,
1784 const struct msg *prompt
1785 /* may be 0 for SENTMSG1 */)
1787 bool_t (*gen)(struct site *st, const struct msg *prompt);
1790 slog(st,LOG_STATE,"entering state %s",state_name(next));
1793 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1794 if (!kex_init(st)) return False;
1796 st->msg1_crossed_logged = False;
1799 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1800 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1801 if (!kex_init(st)) return False;
1805 state_assert(st,st->state==SITE_SENTMSG1);
1806 BUF_FREE(&st->buffer);
1810 state_assert(st,st->state==SITE_SENTMSG2);
1811 BUF_FREE(&st->buffer);
1815 state_assert(st,st->state==SITE_SENTMSG3);
1816 BUF_FREE(&st->buffer);
1820 state_assert(st,st->state==SITE_SENTMSG4);
1821 BUF_FREE(&st->buffer);
1826 fatal("enter_new_state(%s): invalid new state",state_name(next));
1830 if (hacky_par_start_failnow()) return False;
1832 r= gen(st,prompt) && send_msg(st);
1835 st->setup_retries, st->setup_retry_interval,
1840 if (next==SITE_RUN) {
1841 BUF_FREE(&st->buffer); /* Never reused */
1842 st->timeout=0; /* Never retransmit */
1843 activate_new_key(st);
1847 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1848 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1849 in either state, and enter_state_wait() will
1851 enter_state_wait(st);
1855 /* msg7 tells our peer that we're about to forget our key */
1856 static bool_t send_msg7(struct site *st, cstring_t reason)
1858 cstring_t transform_err;
1860 if (current_valid(st) && st->buffer.free
1861 && transport_peers_valid(&st->peers)) {
1862 BUF_ALLOC(&st->buffer,"site:MSG7");
1863 buffer_init(&st->buffer,calculate_max_start_pad());
1864 buf_append_uint32(&st->buffer,LABEL_MSG7);
1865 buf_append_string(&st->buffer,reason);
1866 if (call_transform_forwards(st, st->current.transform,
1867 &st->buffer, &transform_err))
1869 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1870 buf_prepend_uint32(&st->buffer,st->index);
1871 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1872 transport_xmit(st,&st->peers,&st->buffer,True);
1873 BUF_FREE(&st->buffer);
1880 /* We go into this state if our peer becomes uncommunicative. Similar to
1881 the "stop" state, we forget all session keys for a while, before
1882 re-entering the "run" state. */
1883 static void enter_state_wait(struct site *st)
1885 slog(st,LOG_STATE,"entering state WAIT");
1886 st->timeout=st->now+wait_timeout(st);
1887 st->state=SITE_WAIT;
1888 set_link_quality(st);
1889 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1890 /* XXX Erase keys etc. */
1893 static void generate_prod(struct site *st, struct buffer_if *buf)
1896 buf_append_uint32(buf,0);
1897 buf_append_uint32(buf,0);
1898 buf_append_uint32(buf,LABEL_PROD);
1899 buf_append_string(buf,st->localname);
1900 buf_append_string(buf,st->remotename);
1903 static void generate_send_prod(struct site *st,
1904 const struct comm_addr *source)
1906 if (!st->allow_send_prod) return; /* too soon */
1907 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1908 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1910 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1911 st->allow_send_prod=0;
1912 generate_prod(st,&st->scratch);
1913 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1914 dump_packet(st,&st->scratch,source,False,ok);
1917 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1920 int64_t offset=timeout-*now;
1921 if (offset<0) offset=0;
1922 if (offset>INT_MAX) offset=INT_MAX;
1923 if (*timeout_io<0 || offset<*timeout_io)
1928 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1931 struct site *st=sst;
1933 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1936 /* Work out when our next timeout is. The earlier of 'timeout' or
1937 'current.key_timeout'. A stored value of '0' indicates no timeout
1939 site_settimeout(st->timeout, timeout_io);
1940 site_settimeout(st->current.key_timeout, timeout_io);
1941 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1943 return 0; /* success */
1946 static void check_expiry(struct site *st, struct data_key *key,
1949 if (key->key_timeout && *now>key->key_timeout) {
1950 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1954 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1955 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1957 struct site *st=sst;
1960 if (st->timeout && *now>st->timeout) {
1962 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1963 if (!hacky_par_start_failnow())
1965 } else if (st->state==SITE_WAIT) {
1966 enter_state_run(st);
1968 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1972 check_expiry(st,&st->current,"current key");
1973 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1976 /* This function is called by the netlink device to deliver packets
1977 intended for the remote network. The packet is in "raw" wire
1978 format, but is guaranteed to be word-aligned. */
1979 static void site_outgoing(void *sst, struct buffer_if *buf)
1981 struct site *st=sst;
1982 cstring_t transform_err;
1984 if (st->state==SITE_STOP) {
1989 st->allow_send_prod=1;
1991 /* In all other states we consider delivering the packet if we have
1992 a valid key and a valid address to send it to. */
1993 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1994 /* Transform it and send it */
1996 buf_prepend_uint32(buf,LABEL_MSG9);
1997 if (call_transform_forwards(st, st->current.transform,
1998 buf, &transform_err))
2000 buf_prepend_uint32(buf,LABEL_MSG0);
2001 buf_prepend_uint32(buf,st->index);
2002 buf_prepend_uint32(buf,st->current.remote_session_id);
2003 transport_xmit(st,&st->peers,buf,False);
2010 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
2012 initiate_key_setup(st,"outgoing packet",0);
2015 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
2016 uint32_t type, struct msg *m,
2017 struct priomsg *whynot)
2018 /* For packets which are identified by the local and remote names.
2019 * If it has our name and our peer's name in it it's for us. */
2021 struct buffer_if buf[1];
2022 buffer_readonly_clone(buf,buf_in);
2024 if (!unpick_msg(st,type,buf,m)) {
2025 priomsg_update_fixed(whynot, comm_notify_whynot_unpick, "malformed");
2028 #define NAME_MATCHES(lr) \
2029 if (!name_matches(&m->lr, st->lr##name)) { \
2030 if (priomsg_update_fixed(whynot, comm_notify_whynot_name_##lr, \
2031 "unknown " #lr " name: ")) { \
2032 truncmsg_add_packet_string(&whynot->m, m->lr.len, m->lr.name); \
2036 NAME_MATCHES(remote);
2037 NAME_MATCHES(local );
2043 static bool_t we_have_priority(struct site *st, const struct msg *m) {
2044 if (st->local_capabilities & m->remote_capabilities &
2045 CAPAB_PRIORITY_MOBILE) {
2046 if (st->local_mobile) return True;
2047 if (st-> peer_mobile) return False;
2049 return st->our_name_later;
2052 static bool_t setup_late_msg_ok(struct site *st,
2053 const struct buffer_if *buf_in,
2055 const struct comm_addr *source,
2056 struct msg *m /* returned */) {
2057 /* For setup packets which seem from their type like they are
2058 * late. Maybe they came via a different path. All we do is make
2059 * a note of the sending address, iff they look like they are part
2060 * of the current key setup attempt. */
2061 if (!named_for_us(st,buf_in,msgtype,m,0))
2062 /* named_for_us calls unpick_msg which gets the nonces */
2064 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
2065 !consttime_memeq(m->nL,st->localN, NONCELEN))
2066 /* spoof ? from stale run ? who knows */
2068 transport_setup_msgok(st,source);
2072 /* This function is called by the communication device to deliver
2073 packets from our peers.
2074 It should return True if the packet is recognised as being for
2075 this current site instance (and should therefore not be processed
2076 by other sites), even if the packet was otherwise ignored. */
2077 static bool_t site_incoming(void *sst, struct buffer_if *buf,
2078 const struct comm_addr *source,
2079 struct priomsg *whynot)
2081 struct site *st=sst;
2083 if (buf->size < 12) return False;
2085 uint32_t dest=get_uint32(buf->start);
2086 uint32_t msgtype=get_uint32(buf->start+8);
2088 /* initialised by named_for_us, or process_msgN for N!=1 */
2090 if (msgtype==LABEL_MSG1) {
2091 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2093 /* It's a MSG1 addressed to us. Decide what to do about it. */
2094 dump_packet(st,buf,source,True,True);
2095 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
2096 st->state==SITE_WAIT) {
2097 /* We should definitely process it */
2098 transport_compute_setupinit_peers(st,0,0,source);
2099 if (process_msg1(st,buf,source,&msg)) {
2100 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
2101 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
2102 if (entered && st->addresses && st->local_mobile)
2103 /* We must do this as the very last thing, because
2104 the resolver callback might reenter us. */
2105 ensure_resolving(st);
2107 slog(st,LOG_ERROR,"failed to process incoming msg1");
2111 } else if (st->state==SITE_SENTMSG1) {
2112 /* We've just sent a message 1! They may have crossed on
2113 the wire. If we have priority then we ignore the
2114 incoming one, otherwise we process it as usual. */
2115 if (we_have_priority(st,&msg)) {
2117 if (!st->msg1_crossed_logged++)
2118 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
2119 "priority => ignore incoming msg1");
2122 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
2123 "priority => use incoming msg1");
2124 if (process_msg1(st,buf,source,&msg)) {
2125 BUF_FREE(&st->buffer); /* Free our old message 1 */
2126 transport_setup_msgok(st,source);
2127 enter_new_state(st,SITE_SENTMSG2,&msg);
2129 slog(st,LOG_ERROR,"failed to process an incoming "
2130 "crossed msg1 (we have low priority)");
2135 } else if (st->state==SITE_SENTMSG2 ||
2136 st->state==SITE_SENTMSG4) {
2137 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
2138 /* We are ahead in the protocol, but that msg1 had the
2139 * peer's nonce so presumably it is from this key
2140 * exchange run, via a slower route */
2141 transport_setup_msgok(st,source);
2143 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
2148 /* The message 1 was received at an unexpected stage of the
2149 key setup. Well, they lost the race. */
2150 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
2154 if (msgtype==LABEL_PROD) {
2155 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2157 dump_packet(st,buf,source,True,True);
2158 if (st->state!=SITE_RUN) {
2159 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
2160 } else if (current_valid(st)) {
2161 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
2163 initiate_key_setup(st,"peer sent PROD packet",source);
2168 if (dest==st->index) {
2169 /* Explicitly addressed to us */
2170 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
2173 /* If the source is our current peer then initiate a key setup,
2174 because our peer's forgotten the key */
2175 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
2177 initiated = initiate_key_setup(st,"received a NAK",source);
2178 if (!initiated) generate_send_prod(st,source);
2180 slog(st,LOG_SEC,"bad incoming NAK");
2184 process_msg0(st,buf,source);
2187 /* Setup packet: should not have been explicitly addressed
2189 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2192 /* Setup packet: expected only in state SENTMSG1 */
2193 if (st->state!=SITE_SENTMSG1) {
2194 if ((st->state==SITE_SENTMSG3 ||
2195 st->state==SITE_SENTMSG5) &&
2196 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2198 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
2199 } else if (process_msg2(st,buf,source,&msg)) {
2200 transport_setup_msgok(st,source);
2201 enter_new_state(st,SITE_SENTMSG3,&msg);
2203 slog(st,LOG_SEC,"invalid MSG2");
2206 case CASES_MSG3_KNOWN:
2207 /* Setup packet: expected only in state SENTMSG2 */
2208 if (st->state!=SITE_SENTMSG2) {
2209 if ((st->state==SITE_SENTMSG4) &&
2210 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2212 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2213 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2214 transport_setup_msgok(st,source);
2215 enter_new_state(st,SITE_SENTMSG4,&msg);
2217 slog(st,LOG_SEC,"invalid MSG3");
2221 /* Setup packet: expected only in state SENTMSG3 */
2222 if (st->state!=SITE_SENTMSG3) {
2223 if ((st->state==SITE_SENTMSG5) &&
2224 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2226 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2227 } else if (process_msg4(st,buf,source,&msg)) {
2228 transport_setup_msgok(st,source);
2229 enter_new_state(st,SITE_SENTMSG5,&msg);
2231 slog(st,LOG_SEC,"invalid MSG4");
2235 /* Setup packet: expected only in state SENTMSG4 */
2236 /* (may turn up in state RUN if our return MSG6 was lost
2237 and the new key has already been activated. In that
2238 case we discard it. The peer will realise that we
2239 are using the new key when they see our data packets.
2240 Until then the peer's data packets to us get discarded. */
2241 if (st->state==SITE_SENTMSG4) {
2242 if (process_msg5(st,buf,source,st->new_transform)) {
2243 transport_setup_msgok(st,source);
2244 enter_new_state(st,SITE_RUN,&msg);
2246 slog(st,LOG_SEC,"invalid MSG5");
2248 } else if (st->state==SITE_RUN) {
2249 if (process_msg5(st,buf,source,st->current.transform)) {
2250 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2251 transport_setup_msgok(st,source);
2252 create_msg6(st,st->current.transform,
2253 st->current.remote_session_id);
2254 transport_xmit(st,&st->peers,&st->buffer,True);
2255 BUF_FREE(&st->buffer);
2257 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2260 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2264 /* Setup packet: expected only in state SENTMSG5 */
2265 if (st->state!=SITE_SENTMSG5) {
2266 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2267 } else if (process_msg6(st,buf,source)) {
2268 BUF_FREE(&st->buffer); /* Free message 5 */
2269 transport_setup_msgok(st,source);
2270 activate_new_key(st);
2272 slog(st,LOG_SEC,"invalid MSG6");
2276 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2284 priomsg_update_fixed(whynot, comm_notify_whynot_general,
2285 "not MSG1 or PROD; unknown dest index");
2289 static void site_control(void *vst, bool_t run)
2291 struct site *st=vst;
2292 if (run) enter_state_run(st);
2293 else enter_state_stop(st);
2296 static void site_phase_hook(void *sst, uint32_t newphase)
2298 struct site *st=sst;
2300 /* The program is shutting down; tell our peer */
2301 send_msg7(st,"shutting down");
2304 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2306 struct site *st=sst;
2307 dispose_transform(&st->current.transform);
2308 dispose_transform(&st->auxiliary_key.transform);
2309 dispose_transform(&st->new_transform);
2310 /* Not much point overwiting the signing key, since we loaded it
2311 from disk, and it is only valid prospectively if at all,
2313 /* XXX it would be best to overwrite the DH state, because that
2314 _is_ relevant to forward secrecy. However we have no
2315 convenient interface for doing that and in practice gmp has
2316 probably dribbled droppings all over the malloc arena. A good
2317 way to fix this would be to have a privsep child for asymmetric
2318 crypto operations, but that's a task for another day. */
2321 static void setup_sethash(struct site *st, dict_t *dict,
2323 sig_sethash_fn *sethash, void *sigkey_st) {
2325 cfgfatal(loc,"site","other settings imply `hash' key is needed");
2326 sethash(sigkey_st,st->defhash);
2328 #define SETUP_SETHASH(k) do{ \
2330 setup_sethash(st,dict,loc, (k)->sethash,(k)->st); \
2333 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2336 static uint32_t index_sequence;
2344 st->cl.description="site";
2345 st->cl.type=CL_SITE;
2347 st->cl.interface=&st->ops;
2349 st->ops.control=site_control;
2350 st->ops.status=site_status;
2351 st->peerkeys_path=0;
2352 st->peerkeys_tmpl.buffer=0;
2353 st->peerkeys_current=st->peerkeys_kex=0;
2355 /* First parameter must be a dict */
2356 item=list_elem(args,0);
2357 if (!item || item->type!=t_dict)
2358 cfgfatal(loc,"site","parameter must be a dictionary\n");
2360 dict=item->data.dict;
2361 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2362 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2364 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2366 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2368 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2370 /* Sanity check (which also allows the 'sites' file to include
2371 site() closures for all sites including our own): refuse to
2372 talk to ourselves */
2373 if (strcmp(st->localname,st->remotename)==0) {
2374 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2376 if (st->peer_mobile != st->local_mobile)
2377 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2378 " but our local-mobile=%d\n",
2379 st->localname, st->peer_mobile, st->local_mobile);
2383 if (st->peer_mobile && st->local_mobile) {
2384 Message(M_WARNING,"site %s: site is mobile but so are we"
2385 " -> ignoring this site\n", st->remotename);
2390 assert(index_sequence < 0xffffffffUL);
2391 st->index = ++index_sequence;
2392 st->local_capabilities = 0;
2393 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2394 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2396 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2397 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2398 if (!things##_cfg) \
2399 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2400 st->nthings=list_length(things##_cfg); \
2401 NEW_ARY(st->things,st->nthings); \
2402 assert(st->nthings); \
2403 for (i=0; i<st->nthings; i++) { \
2404 item_t *item=list_elem(things##_cfg,i); \
2405 if (item->type!=t_closure) \
2406 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2407 closure_t *cl=item->data.closure; \
2408 if (cl->type!=CL_TYPE) \
2409 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2410 st->things[i]=cl->interface; \
2414 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2416 NEW_ARY(st->commclientinfos, st->ncomms);
2417 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2418 for (i=0; i<st->ncomms; i++) {
2419 st->commclientinfos[i] =
2421 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2424 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2425 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2426 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2428 st->defhash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2430 st->privkeys=find_cl_if(dict,"key-cache",CL_PRIVCACHE,False,"site",loc);
2431 if (!st->privkeys) {
2433 find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2434 SETUP_SETHASH(st->privkey_fixed);
2437 struct sigpubkey_if *fixed_pubkey
2438 =find_cl_if(dict,"key",CL_SIGPUBKEY,False,"site",loc);
2439 st->peerkeys_path=dict_read_string(dict,"peer-keys",fixed_pubkey==0,
2441 if (st->peerkeys_path) {
2442 pathprefix_template_init(&st->peerkeys_tmpl,st->peerkeys_path,
2443 PEERKEYS_SUFFIX_MAXLEN + 1 /* nul */);
2444 st->peerkeys_current=keyset_load(st->peerkeys_path,
2445 &st->scratch,st->log,M_ERR,
2448 fixed_pubkey->dispose(fixed_pubkey->st);
2451 assert(fixed_pubkey);
2452 SETUP_SETHASH(fixed_pubkey);
2453 NEW(st->peerkeys_current);
2454 st->peerkeys_current->refcount=1;
2455 st->peerkeys_current->nkeys=1;
2456 st->peerkeys_current->keys[0].id=keyid_zero;
2457 st->peerkeys_current->keys[0].pubkey=fixed_pubkey;
2458 slog(st,LOG_SIGKEYS,
2459 "using old-style fixed peer public key (no `peer-keys')");
2462 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2464 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2465 else st->remoteport=0;
2467 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2469 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2471 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2472 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2473 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2475 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2476 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2477 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2478 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2479 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2481 st->mobile_peer_expiry= dict_read_number(
2482 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2484 const char *peerskey= st->peer_mobile
2485 ? "mobile-peers-max" : "static-peers-max";
2486 st->transport_peers_max= dict_read_number(
2487 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2488 if (st->transport_peers_max<1 ||
2489 st->transport_peers_max>MAX_PEER_ADDRS) {
2490 cfgfatal(loc,"site", "%s must be in range 1.."
2491 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2494 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2495 st->key_renegotiate_time=st->key_lifetime/2;
2497 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2498 st->key_renegotiate_time=dict_read_number(
2499 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2500 if (st->key_renegotiate_time > st->key_lifetime) {
2501 cfgfatal(loc,"site",
2502 "renegotiate-time must be less than key-lifetime\n");
2505 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2506 log_event_table,"site");
2508 st->resolving_count=0;
2509 st->allow_send_prod=0;
2511 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2513 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2515 /* The information we expect to see in incoming messages of type 1 */
2516 /* fixme: lots of unchecked overflows here, but the results are only
2517 corrupted packets rather than undefined behaviour */
2518 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2520 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2522 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2523 BUF_ALLOC(&st->scratch,"site:scratch");
2525 /* We are interested in poll(), but only for timeouts. We don't have
2526 any fds of our own. */
2527 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2530 st->remote_capabilities=0;
2531 st->chosen_transform=0;
2532 st->current.key_timeout=0;
2533 st->auxiliary_key.key_timeout=0;
2534 transport_peers_clear(st,&st->peers);
2535 transport_peers_clear(st,&st->setup_peers);
2536 /* XXX mlock these */
2537 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2538 st->sharedsecretlen=st->sharedsecretallocd=0;
2541 #define SET_CAPBIT(bit) do { \
2542 uint32_t capflag = 1UL << (bit); \
2543 if (st->local_capabilities & capflag) \
2544 slog(st,LOG_ERROR,"capability bit" \
2545 " %d (%#"PRIx32") reused", (bit), capflag); \
2546 st->local_capabilities |= capflag; \
2549 for (i=0; i<st->ntransforms; i++)
2550 SET_CAPBIT(st->transforms[i]->capab_bit);
2554 if (st->local_mobile || st->peer_mobile)
2555 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2557 /* We need to register the remote networks with the netlink device */
2558 uint32_t netlink_mtu; /* local virtual interface mtu */
2559 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2560 if (!st->mtu_target)
2561 st->mtu_target=netlink_mtu;
2563 for (i=0; i<st->ncomms; i++)
2564 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2566 st->current.transform=0;
2567 st->auxiliary_key.transform=0;
2568 st->new_transform=0;
2569 st->auxiliary_is_new=0;
2571 enter_state_stop(st);
2573 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2574 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2576 return new_closure(&st->cl);
2579 void site_module(dict_t *dict)
2581 add_closure(dict,"site",site_apply);
2585 /***** TRANSPORT PEERS definitions *****/
2587 static void transport_peers_debug(struct site *st, transport_peers *dst,
2588 const char *didwhat,
2589 int nargs, const struct comm_addr *args,
2594 if (!(st->log_events & LOG_PEER_ADDRS))
2595 return; /* an optimisation */
2597 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2598 (dst==&st->peers ? "data" :
2599 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2600 didwhat, nargs, dst->npeers);
2602 for (i=0, argp=(void*)args;
2604 i++, (argp+=stride?stride:sizeof(*args))) {
2605 const struct comm_addr *ca=(void*)argp;
2606 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2607 i, comm_addr_to_string(ca));
2609 for (i=0; i<dst->npeers; i++) {
2610 struct timeval diff;
2611 timersub(tv_now,&dst->peers[i].last,&diff);
2612 const struct comm_addr *ca=&dst->peers[i].addr;
2613 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2614 i, comm_addr_to_string(ca),
2615 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2619 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2620 /* peers must be sorted first */
2621 int previous_peers=peers->npeers;
2622 struct timeval oldest;
2623 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2624 oldest.tv_usec = tv_now->tv_usec;
2625 while (peers->npeers>1 &&
2626 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2628 if (peers->npeers != previous_peers)
2629 transport_peers_debug(st,peers,"expire", 0,0,0);
2632 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2633 const struct comm_addr *ca,
2634 const struct timeval *tv) {
2635 /* returns false if output is full */
2638 if (peers->npeers >= st->transport_peers_max)
2641 for (search=0; search<peers->npeers; search++)
2642 if (comm_addr_equal(&peers->peers[search].addr, ca))
2645 peers->peers[peers->npeers].addr = *ca;
2646 peers->peers[peers->npeers].last = *tv;
2651 static void transport_record_peers(struct site *st, transport_peers *peers,
2652 const struct comm_addr *addrs, int naddrs,
2654 /* We add addrs into peers. The new entries end up at the front
2655 * and displace entries towards the end (perhaps even off the
2656 * end). Any existing matching entries are moved up to the front.
2658 * Caller must first call transport_peers_expire. */
2661 /* avoids debug for uninteresting updates */
2663 for (i=0; i<peers->npeers; i++) {
2664 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2665 memmove(peers->peers+1, peers->peers,
2666 sizeof(peers->peers[0]) * i);
2667 peers->peers[0].addr = addrs[0];
2668 peers->peers[0].last = *tv_now;
2674 int old_npeers=peers->npeers;
2675 transport_peer old_peers[old_npeers];
2676 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2680 for (i=0; i<naddrs; i++) {
2681 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2684 for (i=0; i<old_npeers; i++) {
2685 const transport_peer *old=&old_peers[i];
2686 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2690 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2693 static void transport_expire_record_peers(struct site *st,
2694 transport_peers *peers,
2695 const struct comm_addr *addrs,
2696 int naddrs, const char *m) {
2697 /* Convenience function */
2698 transport_peers_expire(st,peers);
2699 transport_record_peers(st,peers,addrs,naddrs,m);
2702 static bool_t transport_compute_setupinit_peers(struct site *st,
2703 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2704 int n_configured_addrs /* 0 if none or not found */,
2705 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2706 if (!n_configured_addrs && !incoming_packet_addr &&
2707 !transport_peers_valid(&st->peers))
2710 slog(st,LOG_SETUP_INIT,
2711 "using: %d configured addr(s);%s %d old peer addrs(es)",
2713 incoming_packet_addr ? " incoming packet address;" : "",
2716 /* Non-mobile peers try addresses until one is plausible. The
2717 * effect is that this code always tries first the configured
2718 * address if supplied, or otherwise the address of the incoming
2719 * PROD, or finally the existing data peer if one exists; this is
2722 transport_peers_copy(st,&st->setup_peers,&st->peers);
2723 transport_peers_expire(st,&st->setup_peers);
2725 if (incoming_packet_addr)
2726 transport_record_peers(st,&st->setup_peers,
2727 incoming_packet_addr,1, "incoming");
2729 if (n_configured_addrs)
2730 transport_record_peers(st,&st->setup_peers,
2731 configured_addrs,n_configured_addrs, "setupinit");
2733 assert(transport_peers_valid(&st->setup_peers));
2737 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2738 if (st->peer_mobile)
2739 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2741 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2742 if (st->peer_mobile)
2743 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2746 static int transport_peers_valid(transport_peers *peers) {
2747 return peers->npeers;
2749 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2751 transport_peers_debug(st,peers,"clear",0,0,0);
2753 static void transport_peers_copy(struct site *st, transport_peers *dst,
2754 const transport_peers *src) {
2755 dst->npeers=src->npeers;
2756 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2757 transport_peers_debug(st,dst,"copy",
2758 src->npeers, &src->peers->addr, sizeof(*src->peers));
2761 static void transport_resolve_complete(struct site *st,
2762 const struct comm_addr *addrs,
2764 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2766 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2770 static void transport_resolve_complete_tardy(struct site *st,
2771 const struct comm_addr *addrs,
2773 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2774 "resolved tardily");
2777 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2779 const transport_peers *inp) {
2780 /* out and in->peers may be the same region, or nonoverlapping */
2781 const transport_peer *in=inp->peers;
2783 for (slot=0; slot<inp->npeers; slot++) {
2784 if (!(mask & (1U << slot)))
2786 if (!(out==in && slot==*nout_io))
2787 COPY_OBJ(out[*nout_io], in[slot]);
2792 void transport_xmit(struct site *st, transport_peers *peers,
2793 struct buffer_if *buf, bool_t candebug) {
2795 transport_peers_expire(st, peers);
2796 unsigned failed=0; /* bitmask */
2797 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2800 for (slot=0; slot<peers->npeers; slot++) {
2801 transport_peer *peer=&peers->peers[slot];
2802 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2804 dump_packet(st, buf, &peer->addr, False, ok);
2806 failed |= 1U << slot;
2809 if (ok && !st->peer_mobile)
2812 /* Now we need to demote/delete failing addrs: if we are mobile we
2813 * merely demote them; otherwise we delete them. */
2814 if (st->local_mobile) {
2815 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2816 /* `expected' has all the failures at the end already */
2817 if (failed != expected) {
2819 transport_peer failedpeers[nfailed];
2820 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2821 assert(fslot == nfailed);
2823 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2824 assert(wslot+nfailed == peers->npeers);
2825 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2826 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2829 if (failed && peers->npeers > 1) {
2831 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2832 peers->npeers=wslot;
2833 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2838 /***** END of transport peers declarations *****/