1 /* site.c - manage communication with a remote network site */
4 * This file is part of secnet.
5 * See README for full list of copyright holders.
7 * secnet is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3 of the License, or
10 * (at your option) any later version.
12 * secnet is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * version 3 along with secnet; if not, see
19 * https://www.gnu.org/licenses/gpl.html.
22 /* The 'site' code doesn't know anything about the structure of the
23 packets it's transmitting. In fact, under the new netlink
24 configuration scheme it doesn't need to know anything at all about
25 IP addresses, except how to contact its peer. This means it could
26 potentially be used to tunnel other protocols too (IPv6, IPX, plain
27 old Ethernet frames) if appropriate netlink code can be written
28 (and that ought not to be too hard, eg. using the TUN/TAP device to
29 pretend to be an Ethernet interface). */
31 /* At some point in the future the netlink code will be asked for
32 configuration information to go in the PING/PONG packets at the end
33 of the key exchange. */
40 #include <sys/socket.h>
44 #include "unaligned.h"
48 #define SETUP_BUFFER_LEN 2048
50 #define DEFAULT_KEY_LIFETIME (3600*1000) /* [ms] */
51 #define DEFAULT_KEY_RENEGOTIATE_GAP (5*60*1000) /* [ms] */
52 #define DEFAULT_SETUP_RETRIES 5
53 #define DEFAULT_SETUP_RETRY_INTERVAL (2*1000) /* [ms] */
54 #define DEFAULT_WAIT_TIME (20*1000) /* [ms] */
56 #define DEFAULT_MOBILE_KEY_LIFETIME (2*24*3600*1000) /* [ms] */
57 #define DEFAULT_MOBILE_KEY_RENEGOTIATE_GAP (12*3600*1000) /* [ms] */
58 #define DEFAULT_MOBILE_SETUP_RETRIES 30
59 #define DEFAULT_MOBILE_SETUP_RETRY_INTERVAL (1*1000) /* [ms] */
60 #define DEFAULT_MOBILE_WAIT_TIME (10*1000) /* [ms] */
62 #define DEFAULT_MOBILE_PEER_EXPIRY (2*60) /* [s] */
64 #define PEERKEYS_SUFFIX_MAXLEN (sizeof("~incoming")-1)
66 /* Each site can be in one of several possible states. */
69 SITE_STOP - nothing is allowed to happen; tunnel is down;
70 all session keys have been erased
71 -> SITE_RUN upon external instruction
72 SITE_RUN - site up, maybe with valid key
73 -> SITE_RESOLVE upon outgoing packet and no valid key
74 we start name resolution for the other end of the tunnel
75 -> SITE_SENTMSG2 upon valid incoming message 1 and suitable time
76 we send an appropriate message 2
77 SITE_RESOLVE - waiting for name resolution
78 -> SITE_SENTMSG1 upon successful resolution
79 we send an appropriate message 1
80 -> SITE_SENTMSG2 upon valid incoming message 1 (then abort resolution)
81 we abort resolution and
82 -> SITE_WAIT on timeout or resolution failure
84 -> SITE_SENTMSG2 upon valid incoming message 1 from higher priority end
85 -> SITE_SENTMSG3 upon valid incoming message 2
86 -> SITE_WAIT on timeout
88 -> SITE_SENTMSG4 upon valid incoming message 3
89 -> SITE_WAIT on timeout
91 -> SITE_SENTMSG5 upon valid incoming message 4
92 -> SITE_WAIT on timeout
94 -> SITE_RUN upon valid incoming message 5
95 -> SITE_WAIT on timeout
97 -> SITE_RUN upon valid incoming message 6
98 -> SITE_WAIT on timeout
99 SITE_WAIT - failed to establish key; do nothing for a while
100 -> SITE_RUN on timeout
105 #define SITE_RESOLVE 2
106 #define SITE_SENTMSG1 3
107 #define SITE_SENTMSG2 4
108 #define SITE_SENTMSG3 5
109 #define SITE_SENTMSG4 6
110 #define SITE_SENTMSG5 7
113 #define CASES_MSG3_KNOWN LABEL_MSG3: case LABEL_MSG3BIS
117 int32_t site_max_start_pad = 4*4;
119 static cstring_t state_name(uint32_t state)
122 case 0: return "STOP";
123 case 1: return "RUN";
124 case 2: return "RESOLVE";
125 case 3: return "SENTMSG1";
126 case 4: return "SENTMSG2";
127 case 5: return "SENTMSG3";
128 case 6: return "SENTMSG4";
129 case 7: return "SENTMSG5";
130 case 8: return "WAIT";
131 default: return "*bad state*";
137 #define LOG_UNEXPECTED 0x00000001
138 #define LOG_SETUP_INIT 0x00000002
139 #define LOG_SETUP_TIMEOUT 0x00000004
140 #define LOG_ACTIVATE_KEY 0x00000008
141 #define LOG_TIMEOUT_KEY 0x00000010
142 #define LOG_SEC 0x00000020
143 #define LOG_STATE 0x00000040
144 #define LOG_DROP 0x00000080
145 #define LOG_DUMP 0x00000100
146 #define LOG_ERROR 0x00000400
147 #define LOG_PEER_ADDRS 0x00000800
148 #define LOG_SIGKEYS 0x00001000
150 static struct flagstr log_event_table[]={
151 { "unexpected", LOG_UNEXPECTED },
152 { "setup-init", LOG_SETUP_INIT },
153 { "setup-timeout", LOG_SETUP_TIMEOUT },
154 { "activate-key", LOG_ACTIVATE_KEY },
155 { "timeout-key", LOG_TIMEOUT_KEY },
156 { "security", LOG_SEC },
157 { "state-change", LOG_STATE },
158 { "packet-drop", LOG_DROP },
159 { "dump-packets", LOG_DUMP },
160 { "errors", LOG_ERROR },
161 { "peer-addrs", LOG_PEER_ADDRS },
162 { "sigkeys", LOG_SIGKEYS },
163 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
164 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR|LOG_SIGKEYS },
165 { "all", 0xffffffff },
170 /***** TRANSPORT PEERS declarations *****/
172 /* Details of "mobile peer" semantics:
174 - We use the same data structure for the different configurations,
175 but manage it with different algorithms.
177 - We record up to mobile_peers_max peer address/port numbers
178 ("peers") for key setup, and separately up to mobile_peers_max
181 - In general, we make a new set of addrs (see below) when we start
182 a new key exchange; the key setup addrs become the data transport
183 addrs when key setup complets.
185 If our peer is mobile:
187 - We send to all recent addresses of incoming packets, plus
188 initially all configured addresses (which we also expire).
190 - So, we record addrs of good incoming packets, as follows:
191 1. expire any peers last seen >120s ("mobile-peer-expiry") ago
192 2. add the peer of the just received packet to the applicable list
193 (possibly evicting the oldest entries to make room)
194 NB that we do not expire peers until an incoming packet arrives.
196 - If the peer has a configured address or name, we record them the
197 same way, but only as a result of our own initiation of key
198 setup. (We might evict some incoming packet addrs to make room.)
200 - The default number of addrs to keep is 3, or 4 if we have a
201 configured name or address. That's space for two configured
202 addresses (one IPv6 and one IPv4), plus two received addresses.
204 - Outgoing packets are sent to every recorded address in the
205 applicable list. Any unsupported[1] addresses are deleted from
206 the list right away. (This should only happen to configured
207 addresses, of course, but there is no need to check that.)
209 - When we successfully complete a key setup, we merge the key setup
210 peers into the data transfer peers.
212 [1] An unsupported address is one for whose AF we don't have a
213 socket (perhaps because we got EAFNOSUPPORT or some such) or for
214 which sendto gives ENETUNREACH.
216 If neither end is mobile:
218 - When peer initiated the key exchange, we use the incoming packet
221 - When we initiate the key exchange, we try configured addresses
222 until we get one which isn't unsupported then fixate on that.
224 - When we complete a key setup, we replace the data transport peers
225 with those from the key setup.
229 - We can't tell when local network setup changes so we can't cache
230 the unsupported addrs and completely remove the spurious calls to
231 sendto, but we can optimise things a bit by deprioritising addrs
232 which seem to be unsupported.
234 - Use only configured addresses. (Except, that if our peer
235 initiated a key exchange we use the incoming packet address until
236 our name resolution completes.)
238 - When we send a packet, try each address in turn; if addr
239 supported, put that address to the end of the list for future
240 packets, and go onto the next address.
242 - When we complete a key setup, we replace the data transport peers
243 with those from the key setup.
249 struct comm_addr addr;
253 /* configuration information */
254 /* runtime information */
256 transport_peer peers[MAX_PEER_ADDRS];
259 /* Basic operations on transport peer address sets */
260 static void transport_peers_clear(struct site *st, transport_peers *peers);
261 static int transport_peers_valid(transport_peers *peers);
262 static void transport_peers_copy(struct site *st, transport_peers *dst,
263 const transport_peers *src);
265 /* Record address of incoming setup packet; resp. data packet. */
266 static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
267 static void transport_data_msgok(struct site *st, const struct comm_addr *a);
269 /* Initialise the setup addresses. Called before we send the first
270 * packet in a key exchange. If we are the initiator, as a result of
271 * resolve completing (or being determined not to be relevant) or an
272 * incoming PROD; if we are the responder, as a result of the MSG1. */
273 static bool_t transport_compute_setupinit_peers(struct site *st,
274 const struct comm_addr *configured_addrs /* 0 if none or not found */,
275 int n_configured_addrs /* 0 if none or not found */,
276 const struct comm_addr *incoming_packet_addr /* 0 if none */);
278 /* Called if we are the responder in a key setup, when the resolve
279 * completes. transport_compute_setupinit_peers will hvae been called
280 * earlier. If _complete is called, we are still doing the key setup
281 * (and we should use the new values for both the rest of the key
282 * setup and the ongoing data exchange); if _tardy is called, the key
283 * setup is done (either completed or not) and only the data peers are
285 static void transport_resolve_complete(struct site *st,
286 const struct comm_addr *addrs, int naddrs);
287 static void transport_resolve_complete_tardy(struct site *st,
288 const struct comm_addr *addrs, int naddrs);
290 static void transport_xmit(struct site *st, transport_peers *peers,
291 struct buffer_if *buf, bool_t candebug);
293 /***** END of transport peers declarations *****/
297 struct transform_inst_if *transform;
298 uint64_t key_timeout; /* End of life of current key */
299 uint32_t remote_session_id;
305 /* configuration information */
309 bool_t local_mobile, peer_mobile; /* Mobile client support */
310 int32_t transport_peers_max;
311 string_t tunname; /* localname<->remotename by default, used in logs */
312 cstring_t *addresses; /* DNS name or address(es) for bootstrapping, optional */
313 int remoteport; /* Port for bootstrapping, optional */
315 struct netlink_if *netlink;
316 struct comm_if **comms;
317 struct comm_clientinfo **commclientinfos;
319 struct resolver_if *resolver;
321 struct random_if *random;
322 struct privcache_if *privkeys;
323 struct sigprivkey_if *privkey_fixed;
324 struct transform_if **transforms;
328 uint32_t index; /* Index of this site */
329 uint32_t early_capabilities;
330 uint32_t local_capabilities;
331 int32_t setup_retries; /* How many times to send setup packets */
332 int32_t setup_retry_interval; /* Initial timeout for setup packets */
333 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
334 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
335 int32_t key_lifetime; /* How long a key lasts once set up */
336 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
337 after this time, initiate a new
340 bool_t our_name_later; /* our name > peer name */
343 /* runtime information */
345 uint64_t now; /* Most recently seen time */
346 bool_t allow_send_prod;
347 bool_t msg1_crossed_logged;
349 int resolving_n_results_all;
350 int resolving_n_results_stored;
351 struct comm_addr resolving_results[MAX_PEER_ADDRS];
352 const char *peerkeys_path;
353 struct pathprefix_template peerkeys_tmpl;
354 struct peer_keyset *peerkeys_current, *peerkeys_kex;
356 /* The currently established session */
357 struct data_key current;
358 struct data_key auxiliary_key;
359 bool_t auxiliary_is_new;
360 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
361 uint64_t auxiliary_renegotiate_key_time;
362 transport_peers peers; /* Current address(es) of peer for data traffic */
364 /* The current key setup protocol exchange. We can only be
365 involved in one of these at a time. There's a potential for
366 denial of service here (the attacker keeps sending a setup
367 packet; we keep trying to continue the exchange, and have to
368 timeout before we can listen for another setup packet); perhaps
369 we should keep a list of 'bad' sources for setup packets. */
370 uint32_t remote_capabilities;
371 uint16_t remote_adv_mtu;
372 struct transform_if *chosen_transform;
373 uint32_t setup_session_id;
374 transport_peers setup_peers;
375 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
376 uint8_t remoteN[NONCELEN];
377 struct buffer_if buffer; /* Current outgoing key exchange packet */
378 struct buffer_if scratch;
379 int32_t retries; /* Number of retries remaining */
380 uint64_t timeout; /* Timeout for current state */
382 uint8_t *sharedsecret;
383 uint32_t sharedsecretlen, sharedsecretallocd;
384 struct transform_inst_if *new_transform; /* For key setup/verify */
387 static uint32_t event_log_priority(struct site *st, uint32_t event)
389 if (!(event&st->log_events))
392 case LOG_UNEXPECTED: return M_INFO;
393 case LOG_SETUP_INIT: return M_INFO;
394 case LOG_SETUP_TIMEOUT: return M_NOTICE;
395 case LOG_ACTIVATE_KEY: return M_INFO;
396 case LOG_TIMEOUT_KEY: return M_INFO;
397 case LOG_SEC: return M_SECURITY;
398 case LOG_STATE: return M_DEBUG;
399 case LOG_DROP: return M_DEBUG;
400 case LOG_DUMP: return M_DEBUG;
401 case LOG_ERROR: return M_ERR;
402 case LOG_PEER_ADDRS: return M_DEBUG;
403 case LOG_SIGKEYS: return M_INFO;
404 default: return M_ERR;
408 static uint32_t slog_start(struct site *st, uint32_t event)
410 uint32_t class=event_log_priority(st, event);
412 slilog_part(st->log,class,"%s: ",st->tunname);
417 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
419 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
423 class=slog_start(st,event);
425 vslilog_part(st->log,class,msg,ap);
426 slilog_part(st->log,class,"\n");
430 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
432 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
436 vslog(st,event,msg,ap);
440 static void logtimeout(struct site *st, const char *fmt, ...)
442 static void logtimeout(struct site *st, const char *fmt, ...)
444 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
451 slilog_part(st->log,class,"%s: ",st->tunname);
452 vslilog_part(st->log,class,fmt,ap);
456 for (i=0, delim=" (tried ";
457 i<st->setup_peers.npeers;
459 transport_peer *peer=&st->setup_peers.peers[i];
460 const char *s=comm_addr_to_string(&peer->addr);
461 slilog_part(st->log,class,"%s%s",delim,s);
464 slilog_part(st->log,class,")\n");
468 static void set_link_quality(struct site *st);
469 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
470 static void delete_one_key(struct site *st, struct data_key *key,
471 const char *reason /* may be 0 meaning don't log*/,
472 const char *which /* ignored if !reasonn */,
473 uint32_t loglevel /* ignored if !reasonn */);
474 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
475 const struct comm_addr *prod_hint);
476 static void enter_state_run(struct site *st);
477 static bool_t enter_state_resolve(struct site *st);
478 static void decrement_resolving_count(struct site *st, int by);
479 static bool_t enter_new_state(struct site *st,uint32_t next,
480 const struct msg *prompt
481 /* may be 0 for SENTMSG1 */);
482 static void enter_state_wait(struct site *st);
483 static void activate_new_key(struct site *st);
485 static bool_t is_transform_valid(struct transform_inst_if *transform)
487 return transform && transform->valid(transform->st);
490 static bool_t current_valid(struct site *st)
492 return is_transform_valid(st->current.transform);
495 #define DEFINE_CALL_TRANSFORM(fwdrev) \
496 static transform_apply_return \
497 call_transform_##fwdrev(struct site *st, \
498 struct transform_inst_if *transform, \
499 struct buffer_if *buf, \
500 const char **errmsg) \
502 if (!is_transform_valid(transform)) { \
503 *errmsg="transform not set up"; \
504 return transform_apply_err; \
506 return transform->fwdrev(transform->st,buf,errmsg); \
509 DEFINE_CALL_TRANSFORM(forwards)
510 DEFINE_CALL_TRANSFORM(reverse)
512 static void dispose_transform(struct transform_inst_if **transform_var)
514 struct transform_inst_if *transform=*transform_var;
516 transform->delkey(transform->st);
517 transform->destroy(transform->st);
522 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
523 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
524 #define CHECK_TYPE(b,t) do { uint32_t type; \
525 CHECK_AVAIL((b),4); \
526 type=buf_unprepend_uint32((b)); \
527 if (type!=(t)) return False; } while(0)
529 static _Bool type_is_msg23(uint32_t type)
532 case LABEL_MSG2: case CASES_MSG3_KNOWN: return True;
533 default: return False;
536 static _Bool type_is_msg34(uint32_t type)
539 case CASES_MSG3_KNOWN: case LABEL_MSG4: return True;
540 default: return False;
547 struct buffer_if extrainfo;
554 struct parsedname remote;
555 struct parsedname local;
556 uint32_t remote_capabilities;
558 int capab_transformnum;
564 struct alg_msg_data sig;
565 int n_pubkeys_accepted_nom; /* may be > MAX_SIG_KEYS ! */
566 const struct sigkeyid *pubkeys_accepted[MAX_SIG_KEYS];
567 int signing_key_index;
570 static const struct sigkeyid keyid_zero;
572 static int32_t wait_timeout(struct site *st) {
573 int32_t t = st->wait_timeout_mean;
576 st->random->generate(st->random->st,sizeof(factor),&factor);
577 t += (t / 256) * factor;
582 static _Bool set_new_transform(struct site *st, char *pk)
586 /* Make room for the shared key */
587 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
588 assert(st->sharedsecretlen);
589 if (st->sharedsecretlen > st->sharedsecretallocd) {
590 st->sharedsecretallocd=st->sharedsecretlen;
591 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
592 st->sharedsecretallocd,
593 "site:sharedsecret");
596 /* Generate the shared key */
597 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
598 st->sharedsecret,st->sharedsecretlen);
600 /* Set up the transform */
601 struct transform_if *generator=st->chosen_transform;
602 struct transform_inst_if *generated=generator->create(generator->st);
603 ok = generated->setkey(generated->st,st->sharedsecret,
604 st->sharedsecretlen,st->our_name_later);
606 dispose_transform(&st->new_transform);
607 if (!ok) return False;
608 st->new_transform=generated;
610 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
611 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
612 st->chosen_transform->capab_bit,
613 st->local_capabilities, st->remote_capabilities);
618 int32_t lenpos, afternul;
620 static void append_string_xinfo_start(struct buffer_if *buf,
621 struct xinfoadd *xia,
623 /* Helps construct one of the names with additional info as found
624 * in MSG1..4. Call this function first, then append all the
625 * desired extra info (not including the nul byte) to the buffer,
626 * then call append_string_xinfo_done. */
628 xia->lenpos = buf->size;
629 buf_append_string(buf,str);
630 buf_append_uint8(buf,0);
631 xia->afternul = buf->size;
633 static void append_string_xinfo_done(struct buffer_if *buf,
634 struct xinfoadd *xia)
636 /* we just need to adjust the string length */
637 if (buf->size == xia->afternul) {
638 /* no extra info, strip the nul too */
639 buf_unappend_uint8(buf);
641 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
645 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
646 out using a transform of config data supplied by netlink */
647 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what,
648 const struct msg *prompt
649 /* may be 0 for MSG1 */)
655 st->retries=st->setup_retries;
656 BUF_ALLOC(&st->buffer,what);
657 buffer_init(&st->buffer,0);
658 buf_append_uint32(&st->buffer,
659 (type==LABEL_MSG1?0:st->setup_session_id));
660 buf_append_uint32(&st->buffer,st->index);
661 buf_append_uint32(&st->buffer,type);
664 append_string_xinfo_start(&st->buffer,&xia,st->localname);
665 buf_append_uint32(&st->buffer,st->local_capabilities);
666 if (type_is_msg34(type)) {
667 buf_append_uint16(&st->buffer,st->mtu_target);
669 if (type_is_msg23(type)) {
670 buf_append_uint8(&st->buffer,st->peerkeys_kex->nkeys);
671 for (ki=0; ki<st->peerkeys_kex->nkeys; ki++) {
672 struct peer_pubkey *pk = &st->peerkeys_kex->keys[ki];
673 BUF_ADD_OBJ(append,&st->buffer,pk->id);
676 struct sigprivkey_if *privkey=0;
677 if (type_is_msg34(type)) {
678 assert(prompt->n_pubkeys_accepted_nom>0);
680 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
682 const struct sigkeyid *kid=prompt->pubkeys_accepted[ki];
684 privkey=st->privkeys->lookup(st->privkeys->st,kid,st->log);
685 if (privkey) goto privkey_found;
687 if (sigkeyid_equal(&keyid_zero,kid)) {
688 privkey=st->privkey_fixed;
693 uint32_t class = slog_start(st,LOG_ERROR);
695 slilog_part(st->log,class,"no suitable private key, peer wanted");
697 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
699 slilog_part(st->log,class, " " SIGKEYID_PR_FMT,
700 SIGKEYID_PR_VAL(prompt->pubkeys_accepted[ki]));
702 if (prompt->n_pubkeys_accepted_nom > MAX_SIG_KEYS)
703 slilog_part(st->log,class," +%d",
704 prompt->n_pubkeys_accepted_nom - MAX_SIG_KEYS);
705 slilog_part(st->log,class,"\n");
710 slog(st,LOG_SIGKEYS,"using private key #%d " SIGKEYID_PR_FMT,
711 ki, SIGKEYID_PR_VAL(prompt->pubkeys_accepted[ki]));
712 buf_append_uint8(&st->buffer,ki);
715 append_string_xinfo_done(&st->buffer,&xia);
717 buf_append_string(&st->buffer,st->remotename);
718 BUF_ADD_OBJ(append,&st->buffer,st->localN);
719 if (type==LABEL_MSG1) return True;
720 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
721 if (type==LABEL_MSG2) return True;
723 if (hacky_par_mid_failnow()) return False;
725 if (MSGMAJOR(type) == 3) do {
726 minor = MSGMINOR(type);
727 if (minor < 1) break;
728 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
731 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
732 buf_append_string(&st->buffer,dhpub);
735 bool_t ok=privkey->sign(privkey->st,
746 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
749 nm->len=buf_unprepend_uint16(msg);
750 CHECK_AVAIL(msg,nm->len);
751 nm->name=buf_unprepend(msg,nm->len);
752 uint8_t *nul=memchr(nm->name,0,nm->len);
754 buffer_readonly_view(&nm->extrainfo,0,0);
756 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
757 nm->len=nul-nm->name;
762 static bool_t unpick_msg(struct site *st, uint32_t type,
763 struct buffer_if *msg, struct msg *m)
767 m->n_pubkeys_accepted_nom=-1;
768 m->capab_transformnum=-1;
769 m->signing_key_index=-1;
770 m->hashstart=msg->start;
772 m->dest=buf_unprepend_uint32(msg);
774 m->source=buf_unprepend_uint32(msg);
775 CHECK_TYPE(msg,type);
776 if (!unpick_name(msg,&m->remote)) return False;
777 m->remote_capabilities=0;
779 if (m->remote.extrainfo.size) {
780 CHECK_AVAIL(&m->remote.extrainfo,4);
781 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
783 if (type_is_msg34(type) && m->remote.extrainfo.size) {
784 CHECK_AVAIL(&m->remote.extrainfo,2);
785 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
787 if (type_is_msg23(type) && m->remote.extrainfo.size) {
788 m->n_pubkeys_accepted_nom = buf_unprepend_uint8(&m->remote.extrainfo);
789 if (!m->n_pubkeys_accepted_nom) return False;
791 for (ki_nom=0; ki_nom<m->n_pubkeys_accepted_nom; ki_nom++) {
792 CHECK_AVAIL(&m->remote.extrainfo,KEYIDSZ);
793 struct sigkeyid *kid = buf_unprepend(&m->remote.extrainfo,KEYIDSZ);
794 if (ki_nom<MAX_SIG_KEYS) m->pubkeys_accepted[ki_nom] = kid;
797 m->n_pubkeys_accepted_nom = 1;
798 m->pubkeys_accepted[0] = &keyid_zero;
800 if (type_is_msg34(type) && m->remote.extrainfo.size) {
801 m->signing_key_index=buf_unprepend_uint8(&m->remote.extrainfo);
803 m->signing_key_index=0;
805 if (!unpick_name(msg,&m->local)) return False;
806 if (type==LABEL_PROD) {
810 CHECK_AVAIL(msg,NONCELEN);
811 m->nR=buf_unprepend(msg,NONCELEN);
812 if (type==LABEL_MSG1) {
816 CHECK_AVAIL(msg,NONCELEN);
817 m->nL=buf_unprepend(msg,NONCELEN);
818 if (type==LABEL_MSG2) {
822 if (MSGMAJOR(type) == 3) do {
823 minor = MSGMINOR(type);
824 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
825 if (minor < (minminor)) \
826 m->capab_##kind##num = (dflt); \
828 CHECK_AVAIL(msg, 1); \
829 m->capab_##kind##num = buf_unprepend_uint8(msg); \
832 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
833 #undef MAYBE_READ_CAP
836 m->pklen=buf_unprepend_uint16(msg);
837 CHECK_AVAIL(msg,m->pklen);
838 m->pk=buf_unprepend(msg,m->pklen);
839 m->hashlen=msg->start-m->hashstart;
841 if (m->signing_key_index < 0 ||
842 m->signing_key_index >= st->peerkeys_kex->nkeys) {
845 struct sigpubkey_if *pubkey=
846 st->peerkeys_kex->keys[m->signing_key_index].pubkey;
847 if (!pubkey->unpick(pubkey->st,msg,&m->sig)) {
856 static bool_t name_matches(const struct parsedname *nm, const char *expected)
858 int expected_len=strlen(expected);
860 nm->len == expected_len &&
861 !memcmp(nm->name, expected, expected_len);
864 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
867 if (type==LABEL_MSG1) return True;
869 /* Check that the site names and our nonce have been sent
870 back correctly, and then store our peer's nonce. */
871 if (!name_matches(&m->remote,st->remotename)) {
872 *error="wrong remote site name";
875 if (!name_matches(&m->local,st->localname)) {
876 *error="wrong local site name";
879 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
880 *error="wrong locally-generated nonce";
883 if (type==LABEL_MSG2) return True;
884 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
885 *error="wrong remotely-generated nonce";
888 /* MSG3 has complicated rules about capabilities, which are
889 * handled in process_msg3. */
890 if (MSGMAJOR(type) == 3) return True;
891 if (m->remote_capabilities!=st->remote_capabilities) {
892 *error="remote capabilities changed";
895 if (type==LABEL_MSG4) return True;
896 *error="unknown message type";
900 static void peerkeys_maybe_incorporate(struct site *st, const char *file,
901 const char *whatmore,
904 struct peer_keyset *atsuffix=
905 keyset_load(file,&st->scratch,st->log,logcl_enoent);
906 if (!atsuffix) return;
908 if (st->peerkeys_current &&
909 serial_cmp(atsuffix->serial,st->peerkeys_current->serial) <= 0) {
910 slog(st,LOG_SIGKEYS,"keys from %s%s are older, discarding",
912 keyset_dispose(&atsuffix);
914 if (r) slog(st,LOG_ERROR,"failed to remove old key update %s: %s\n",
915 st->peerkeys_tmpl.buffer,strerror(errno));
918 slog(st,LOG_SIGKEYS,"keys from %s%s are newer, installing",
920 keyset_dispose(&st->peerkeys_current);
921 st->peerkeys_current=atsuffix;
922 int r=rename(file,st->peerkeys_path);
923 if (r) slog(st,LOG_ERROR,"failed to install key update %s as %s: %s\n",
924 st->peerkeys_tmpl.buffer,st->peerkeys_path,
929 static void peerkeys_check_for_update(struct site *st)
931 if (!st->peerkeys_path) return;
933 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~proc");
934 peerkeys_maybe_incorporate(st,st->peerkeys_tmpl.buffer,
935 " (found old update)",
938 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~update");
939 const char *inputp=st->peerkeys_tmpl.buffer;
940 if (access(inputp,R_OK)) {
942 slog(st,LOG_ERROR,"cannot access peer key update file %s\n",
947 buffer_init(&st->scratch,0);
948 BUF_ADD_BYTES(append,&st->scratch,
949 st->peerkeys_tmpl.buffer,
950 strlen(st->peerkeys_tmpl.buffer)+1);
951 inputp=st->scratch.start;
953 pathprefix_template_setsuffix(&st->peerkeys_tmpl,"~proc");
954 const char *oursp=st->peerkeys_tmpl.buffer;
956 int r=rename(inputp,oursp);
958 slog(st,LOG_ERROR,"failed to claim key update file %s as %s: %s",
959 inputp,oursp,strerror(errno));
963 peerkeys_maybe_incorporate(st,oursp," (update)",M_ERR);
967 static bool_t kex_init(struct site *st)
969 keyset_dispose(&st->peerkeys_kex);
970 peerkeys_check_for_update(st);
971 if (!st->peerkeys_current) {
972 slog(st,LOG_SETUP_INIT,"no peer public keys, abandoning key setup");
975 st->peerkeys_kex = keyset_dup(st->peerkeys_current);
976 st->random->generate(st->random->st,NONCELEN,st->localN);
980 static bool_t generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
983 generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
986 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
987 const struct comm_addr *src,
990 /* We've already determined we're in an appropriate state to
991 process an incoming MSG1, and that the MSG1 has correct values
994 st->setup_session_id=m->source;
995 st->remote_capabilities=m->remote_capabilities;
996 memcpy(st->remoteN,m->nR,NONCELEN);
1000 static bool_t generate_msg2(struct site *st,
1001 const struct msg *prompt_may_be_null)
1004 generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
1007 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
1008 const struct comm_addr *src,
1009 struct msg *m /* returned */)
1013 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
1014 if (!check_msg(st,LABEL_MSG2,m,&err)) {
1015 slog(st,LOG_SEC,"msg2: %s",err);
1018 st->setup_session_id=m->source;
1019 st->remote_capabilities=m->remote_capabilities;
1021 /* Select the transform to use */
1023 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
1024 if (!remote_crypto_caps)
1025 /* old secnets only had this one transform */
1026 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
1028 #define CHOOSE_CRYPTO(kind, whats) do { \
1029 struct kind##_if *iface; \
1030 uint32_t bit, ours = 0; \
1032 for (i= 0; i < st->n##kind##s; i++) { \
1033 iface=st->kind##s[i]; \
1034 bit = 1UL << iface->capab_bit; \
1035 if (bit & remote_crypto_caps) goto kind##_found; \
1038 slog(st,LOG_ERROR,"no " whats " in common" \
1039 " (us %#"PRIx32"; them: %#"PRIx32")", \
1040 st->local_capabilities & ours, remote_crypto_caps); \
1043 st->chosen_##kind = iface; \
1046 CHOOSE_CRYPTO(transform, "transforms");
1048 #undef CHOOSE_CRYPTO
1050 memcpy(st->remoteN,m->nR,NONCELEN);
1054 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
1056 /* Now we have our nonce and their nonce. Think of a secret key,
1057 and create message number 3. */
1058 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1059 return generate_msg(st,
1060 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
1063 "site:MSG3",prompt);
1066 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
1068 /* Check signature and store g^x mod m */
1071 if (m->signing_key_index >= 0) {
1072 if (m->signing_key_index >= st->peerkeys_kex->nkeys)
1074 ki=m->signing_key_index;
1076 for (ki=0; ki<st->peerkeys_kex->nkeys; ki++)
1077 if (sigkeyid_equal(&keyid_zero,&st->peerkeys_kex->keys[ki].id))
1081 "peer signed with keyid zero, which we do not accept");
1085 struct sigpubkey_if *pubkey=st->peerkeys_kex->keys[ki].pubkey;
1087 if (!pubkey->check(pubkey->st,
1088 m->hashstart,m->hashlen,
1090 slog(st,LOG_SEC,"msg3/msg4 signature failed check!"
1091 " (key #%d " SIGKEYID_PR_FMT ")",
1092 ki, SIGKEYID_PR_VAL(&st->peerkeys_kex->keys[ki].id));
1095 slog(st,LOG_SIGKEYS,"verified peer signature with key #%d "
1096 SIGKEYID_PR_FMT, ki,
1097 SIGKEYID_PR_VAL(&st->peerkeys_kex->keys[ki].id));
1099 st->remote_adv_mtu=m->remote_mtu;
1104 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
1105 const struct comm_addr *src, uint32_t msgtype,
1106 struct msg *m /* returned */)
1111 case CASES_MSG3_KNOWN: break;
1115 if (!unpick_msg(st,msgtype,msg3,m)) return False;
1116 if (!check_msg(st,msgtype,m,&err)) {
1117 slog(st,LOG_SEC,"msg3: %s",err);
1120 uint32_t capab_adv_late = m->remote_capabilities
1121 & ~st->remote_capabilities & st->early_capabilities;
1122 if (capab_adv_late) {
1123 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
1124 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
1125 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
1129 #define CHOSE_CRYPTO(kind, what) do { \
1130 struct kind##_if *iface; \
1132 for (i=0; i<st->n##kind##s; i++) { \
1133 iface=st->kind##s[i]; \
1134 if (iface->capab_bit == m->capab_##kind##num) \
1135 goto kind##_found; \
1137 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
1138 m->capab_##kind##num); \
1141 st->chosen_##kind=iface; \
1144 CHOSE_CRYPTO(transform, "transform");
1148 if (!process_msg3_msg4(st,m))
1151 /* Update our idea of the remote site's capabilities, now that we've
1152 * verified that its message was authentic.
1154 * Our previous idea of the remote site's capabilities came from the
1155 * unauthenticated MSG1. We've already checked that this new message
1156 * doesn't change any of the bits we relied upon in the past, but it may
1157 * also have set additional capability bits. We simply throw those away
1158 * now, and use the authentic capabilities from this MSG3. */
1159 st->remote_capabilities=m->remote_capabilities;
1161 /* Terminate their DH public key with a '0' */
1163 /* Invent our DH secret key */
1164 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
1166 /* Generate the shared key and set up the transform */
1167 if (!set_new_transform(st,m->pk)) return False;
1172 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
1174 /* We have both nonces, their public key and our private key. Generate
1175 our public key, sign it and send it to them. */
1176 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
1179 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
1180 const struct comm_addr *src,
1181 struct msg *m /* returned */)
1185 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
1186 if (!check_msg(st,LABEL_MSG4,m,&err)) {
1187 slog(st,LOG_SEC,"msg4: %s",err);
1191 if (!process_msg3_msg4(st,m))
1194 /* Terminate their DH public key with a '0' */
1197 /* Generate the shared key and set up the transform */
1198 if (!set_new_transform(st,m->pk)) return False;
1209 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1212 CHECK_AVAIL(msg0,4);
1213 m->dest=buf_unprepend_uint32(msg0);
1214 CHECK_AVAIL(msg0,4);
1215 m->source=buf_unprepend_uint32(msg0);
1216 CHECK_AVAIL(msg0,4);
1217 m->type=buf_unprepend_uint32(msg0);
1219 /* Leaves transformed part of buffer untouched */
1222 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1224 cstring_t transform_err;
1226 BUF_ALLOC(&st->buffer,"site:MSG5");
1227 /* We are going to add four words to the message */
1228 buffer_init(&st->buffer,calculate_max_start_pad());
1229 /* Give the netlink code an opportunity to put its own stuff in the
1230 message (configuration information, etc.) */
1231 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1232 if (call_transform_forwards(st,st->new_transform,
1233 &st->buffer,&transform_err))
1235 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1236 buf_prepend_uint32(&st->buffer,st->index);
1237 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1239 st->retries=st->setup_retries;
1243 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1244 const struct comm_addr *src,
1245 struct transform_inst_if *transform)
1248 cstring_t transform_err;
1250 if (!unpick_msg0(st,msg5,&m)) return False;
1252 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1253 /* There's a problem */
1254 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1257 /* Buffer should now contain untransformed PING packet data */
1258 CHECK_AVAIL(msg5,4);
1259 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1260 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1263 /* Older versions of secnet used to write some config data here
1264 * which we ignore. So we don't CHECK_EMPTY */
1268 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1269 uint32_t session_id)
1271 cstring_t transform_err;
1273 BUF_ALLOC(&st->buffer,"site:MSG6");
1274 /* We are going to add four words to the message */
1275 buffer_init(&st->buffer,calculate_max_start_pad());
1276 /* Give the netlink code an opportunity to put its own stuff in the
1277 message (configuration information, etc.) */
1278 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1279 transform_apply_return problem =
1280 call_transform_forwards(st,transform,
1281 &st->buffer,&transform_err);
1283 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1284 buf_prepend_uint32(&st->buffer,st->index);
1285 buf_prepend_uint32(&st->buffer,session_id);
1288 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1290 if (!is_transform_valid(st->new_transform))
1292 create_msg6(st,st->new_transform,st->setup_session_id);
1293 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1297 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1298 const struct comm_addr *src)
1301 cstring_t transform_err;
1303 if (!unpick_msg0(st,msg6,&m)) return False;
1305 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1306 /* There's a problem */
1307 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1310 /* Buffer should now contain untransformed PING packet data */
1311 CHECK_AVAIL(msg6,4);
1312 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1313 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1316 /* Older versions of secnet used to write some config data here
1317 * which we ignore. So we don't CHECK_EMPTY */
1321 static transform_apply_return
1322 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1323 const struct comm_addr *src)
1325 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1327 transform_apply_return problem;
1329 if (!unpick_msg0(st,msg0,&m)) return False;
1331 /* Keep a copy so we can try decrypting it with multiple keys */
1332 buffer_copy(&st->scratch, msg0);
1334 problem = call_transform_reverse(st,st->current.transform,
1335 msg0,&transform_err);
1337 if (!st->auxiliary_is_new)
1338 delete_one_key(st,&st->auxiliary_key,
1339 "peer has used new key","auxiliary key",LOG_SEC);
1342 if (transform_apply_return_badseq(problem))
1345 buffer_copy(msg0, &st->scratch);
1346 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1349 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1350 if (st->auxiliary_is_new) {
1351 /* We previously timed out in state SENTMSG5 but it turns
1352 * out that our peer did in fact get our MSG5 and is
1353 * using the new key. So we should switch to it too. */
1354 /* This is a bit like activate_new_key. */
1357 st->current=st->auxiliary_key;
1358 st->auxiliary_key=t;
1360 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1361 "previous key",LOG_SEC);
1362 st->auxiliary_is_new=0;
1363 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1367 if (transform_apply_return_badseq(problem))
1370 if (st->state==SITE_SENTMSG5) {
1371 buffer_copy(msg0, &st->scratch);
1372 problem = call_transform_reverse(st,st->new_transform,
1375 /* It looks like we didn't get the peer's MSG6 */
1376 /* This is like a cut-down enter_new_state(SITE_RUN) */
1377 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1378 BUF_FREE(&st->buffer);
1380 activate_new_key(st);
1381 return 0; /* do process the data in this packet */
1383 if (transform_apply_return_badseq(problem))
1387 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1388 transform_err,auxkey_err,newkey_err);
1389 initiate_key_setup(st,"incoming message would not decrypt",0);
1390 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1395 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1400 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1401 const struct comm_addr *src)
1404 transform_apply_return problem;
1406 problem = decrypt_msg0(st,msg0,src);
1407 if (problem==transform_apply_seqdupe) {
1408 /* We recently received another copy of this packet, maybe due
1409 * to polypath. That's not a problem; indeed, for the
1410 * purposes of transport address management it is a success.
1411 * But we don't want to process the packet. */
1412 transport_data_msgok(st,src);
1418 CHECK_AVAIL(msg0,4);
1419 type=buf_unprepend_uint32(msg0);
1422 /* We must forget about the current session. */
1423 delete_keys(st,"request from peer",LOG_SEC);
1424 /* probably, the peer is shutting down, and this is going to fail,
1425 * but we need to be trying to bring the link up again */
1427 initiate_key_setup(st,"peer requested key teardown",0);
1430 /* Deliver to netlink layer */
1431 st->netlink->deliver(st->netlink->st,msg0);
1432 transport_data_msgok(st,src);
1433 /* See whether we should start negotiating a new key */
1434 if (st->now > st->renegotiate_key_time)
1435 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1438 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1445 static void dump_packet(struct site *st, struct buffer_if *buf,
1446 const struct comm_addr *addr, bool_t incoming,
1449 uint32_t dest=get_uint32(buf->start);
1450 uint32_t source=get_uint32(buf->start+4);
1451 uint32_t msgtype=get_uint32(buf->start+8);
1453 if (st->log_events & LOG_DUMP)
1454 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1455 st->tunname,incoming?"incoming":"outgoing",
1456 dest,source,msgtype,comm_addr_to_string(addr),
1460 static bool_t comm_addr_sendmsg(struct site *st,
1461 const struct comm_addr *dest,
1462 struct buffer_if *buf)
1465 struct comm_clientinfo *commclientinfo = 0;
1467 for (i=0; i < st->ncomms; i++) {
1468 if (st->comms[i] == dest->comm) {
1469 commclientinfo = st->commclientinfos[i];
1473 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1476 static uint32_t site_status(void *st)
1481 static bool_t send_msg(struct site *st)
1483 if (st->retries>0) {
1484 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1485 st->timeout=st->now+st->setup_retry_interval;
1488 } else if (st->state==SITE_SENTMSG5) {
1489 logtimeout(st,"timed out sending MSG5, stashing new key");
1490 /* We stash the key we have produced, in case it turns out that
1491 * our peer did see our MSG5 after all and starts using it. */
1492 /* This is a bit like some of activate_new_key */
1493 struct transform_inst_if *t;
1494 t=st->auxiliary_key.transform;
1495 st->auxiliary_key.transform=st->new_transform;
1496 st->new_transform=t;
1497 dispose_transform(&st->new_transform);
1499 st->auxiliary_is_new=1;
1500 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1501 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1502 st->auxiliary_key.remote_session_id=st->setup_session_id;
1504 enter_state_wait(st);
1507 logtimeout(st,"timed out sending key setup packet "
1508 "(in state %s)",state_name(st->state));
1509 enter_state_wait(st);
1514 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1515 int stored_naddrs, int all_naddrs,
1516 const char *address, const char *failwhy)
1518 struct site *st=sst;
1520 if (!stored_naddrs) {
1521 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1523 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1524 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1526 int space=st->transport_peers_max-st->resolving_n_results_stored;
1527 int n_tocopy=MIN(stored_naddrs,space);
1528 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1531 st->resolving_n_results_stored += n_tocopy;
1532 st->resolving_n_results_all += all_naddrs;
1535 decrement_resolving_count(st,1);
1538 static void decrement_resolving_count(struct site *st, int by)
1540 assert(st->resolving_count>0);
1541 st->resolving_count-=by;
1543 if (st->resolving_count)
1546 /* OK, we are done with them all. Handle combined results. */
1548 const struct comm_addr *addrs=st->resolving_results;
1549 int naddrs=st->resolving_n_results_stored;
1550 assert(naddrs<=st->transport_peers_max);
1553 if (naddrs != st->resolving_n_results_all) {
1554 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1555 " yielded too many results (%d > %d), some ignored",
1556 st->resolving_n_results_all, naddrs);
1558 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1559 naddrs, iaddr_to_string(&addrs[0].ia));;
1562 switch (st->state) {
1564 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1565 enter_new_state(st,SITE_SENTMSG1,0);
1567 /* Can't figure out who to try to to talk to */
1568 slog(st,LOG_SETUP_INIT,
1569 "key exchange failed: cannot find peer address");
1570 enter_state_run(st);
1573 case SITE_SENTMSG1: case SITE_SENTMSG2:
1574 case SITE_SENTMSG3: case SITE_SENTMSG4:
1577 /* We start using the address immediately for data too.
1578 * It's best to store it in st->peers now because we might
1579 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1580 * the new key (without updating the data peer addrs). */
1581 transport_resolve_complete(st,addrs,naddrs);
1582 } else if (st->local_mobile) {
1583 /* We can't let this rest because we may have a peer
1584 * address which will break in the future. */
1585 slog(st,LOG_SETUP_INIT,"resolution failed: "
1586 "abandoning key exchange");
1587 enter_state_wait(st);
1589 slog(st,LOG_SETUP_INIT,"resolution failed: "
1590 " continuing to use source address of peer's packets"
1591 " for key exchange and ultimately data");
1596 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1597 " updating peer address(es)");
1598 transport_resolve_complete_tardy(st,addrs,naddrs);
1599 } else if (st->local_mobile) {
1600 /* Not very good. We should queue (another) renegotiation
1601 * so that we can update the peer address. */
1602 st->key_renegotiate_time=st->now+wait_timeout(st);
1604 slog(st,LOG_SETUP_INIT,"resolution failed: "
1605 " continuing to use source address of peer's packets");
1615 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1616 const struct comm_addr *prod_hint)
1618 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1619 if (st->state!=SITE_RUN) return False;
1620 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1621 if (st->addresses) {
1622 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1623 return enter_state_resolve(st);
1624 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1625 return enter_new_state(st,SITE_SENTMSG1,0);
1627 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1631 static void activate_new_key(struct site *st)
1633 struct transform_inst_if *t;
1635 /* We have three transform instances, which we swap between old,
1637 t=st->auxiliary_key.transform;
1638 st->auxiliary_key.transform=st->current.transform;
1639 st->current.transform=st->new_transform;
1640 st->new_transform=t;
1641 dispose_transform(&st->new_transform);
1644 st->auxiliary_is_new=0;
1645 st->auxiliary_key.key_timeout=st->current.key_timeout;
1646 st->current.key_timeout=st->now+st->key_lifetime;
1647 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1648 transport_peers_copy(st,&st->peers,&st->setup_peers);
1649 st->current.remote_session_id=st->setup_session_id;
1651 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1652 * But their mtu be unspecified, in which case we just use ours. */
1653 uint32_t intersite_mtu=
1654 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1655 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1657 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1658 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1659 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1660 enter_state_run(st);
1663 static void delete_one_key(struct site *st, struct data_key *key,
1664 cstring_t reason, cstring_t which, uint32_t loglevel)
1666 if (!is_transform_valid(key->transform)) return;
1667 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1668 dispose_transform(&key->transform);
1672 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1674 if (current_valid(st)) {
1675 slog(st,loglevel,"session closed (%s)",reason);
1677 delete_one_key(st,&st->current,0,0,0);
1678 set_link_quality(st);
1680 delete_one_key(st,&st->auxiliary_key,0,0,0);
1683 static void state_assert(struct site *st, bool_t ok)
1685 if (!ok) fatal("site:state_assert");
1688 static void enter_state_stop(struct site *st)
1690 st->state=SITE_STOP;
1692 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1693 dispose_transform(&st->new_transform);
1696 static void set_link_quality(struct site *st)
1699 if (current_valid(st))
1700 quality=LINK_QUALITY_UP;
1701 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1702 quality=LINK_QUALITY_DOWN;
1703 else if (st->addresses)
1704 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1705 else if (transport_peers_valid(&st->peers))
1706 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1708 quality=LINK_QUALITY_DOWN;
1710 st->netlink->set_quality(st->netlink->st,quality);
1713 static void enter_state_run(struct site *st)
1715 slog(st,LOG_STATE,"entering state RUN%s",
1716 current_valid(st) ? " (keyed)" : " (unkeyed)");
1720 st->setup_session_id=0;
1721 transport_peers_clear(st,&st->setup_peers);
1722 keyset_dispose(&st->peerkeys_kex);
1723 FILLZERO(st->localN);
1724 FILLZERO(st->remoteN);
1725 dispose_transform(&st->new_transform);
1726 memset(st->dhsecret,0,st->dh->len);
1727 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1728 set_link_quality(st);
1730 if (st->keepalive && !current_valid(st))
1731 initiate_key_setup(st, "keepalive", 0);
1734 static bool_t ensure_resolving(struct site *st)
1736 /* Reentrancy hazard: may call site_resolve_callback and hence
1737 * enter_new_state, enter_state_* and generate_msg*. */
1738 if (st->resolving_count)
1741 assert(st->addresses);
1743 /* resolver->request might reentrantly call site_resolve_callback
1744 * which will decrement st->resolving, so we need to increment it
1745 * twice beforehand to prevent decrement from thinking we're
1746 * finished, and decrement it ourselves. Alternatively if
1747 * everything fails then there are no callbacks due and we simply
1748 * set it to 0 and return false.. */
1749 st->resolving_n_results_stored=0;
1750 st->resolving_n_results_all=0;
1751 st->resolving_count+=2;
1752 const char **addrp=st->addresses;
1753 const char *address;
1755 for (; (address=*addrp++); ) {
1756 bool_t ok = st->resolver->request(st->resolver->st,address,
1757 st->remoteport,st->comms[0],
1758 site_resolve_callback,st);
1760 st->resolving_count++;
1764 st->resolving_count=0;
1767 decrement_resolving_count(st,2);
1771 static bool_t enter_state_resolve(struct site *st)
1773 /* Reentrancy hazard! See ensure_resolving. */
1774 state_assert(st,st->state==SITE_RUN);
1775 slog(st,LOG_STATE,"entering state RESOLVE");
1776 st->state=SITE_RESOLVE;
1777 return ensure_resolving(st);
1780 static bool_t enter_new_state(struct site *st, uint32_t next,
1781 const struct msg *prompt
1782 /* may be 0 for SENTMSG1 */)
1784 bool_t (*gen)(struct site *st, const struct msg *prompt);
1787 slog(st,LOG_STATE,"entering state %s",state_name(next));
1790 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1791 if (!kex_init(st)) return False;
1793 st->msg1_crossed_logged = False;
1796 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1797 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1798 if (!kex_init(st)) return False;
1802 state_assert(st,st->state==SITE_SENTMSG1);
1803 BUF_FREE(&st->buffer);
1807 state_assert(st,st->state==SITE_SENTMSG2);
1808 BUF_FREE(&st->buffer);
1812 state_assert(st,st->state==SITE_SENTMSG3);
1813 BUF_FREE(&st->buffer);
1817 state_assert(st,st->state==SITE_SENTMSG4);
1818 BUF_FREE(&st->buffer);
1823 fatal("enter_new_state(%s): invalid new state",state_name(next));
1827 if (hacky_par_start_failnow()) return False;
1829 r= gen(st,prompt) && send_msg(st);
1832 st->setup_retries, st->setup_retry_interval,
1837 if (next==SITE_RUN) {
1838 BUF_FREE(&st->buffer); /* Never reused */
1839 st->timeout=0; /* Never retransmit */
1840 activate_new_key(st);
1844 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1845 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1846 in either state, and enter_state_wait() will
1848 enter_state_wait(st);
1852 /* msg7 tells our peer that we're about to forget our key */
1853 static bool_t send_msg7(struct site *st, cstring_t reason)
1855 cstring_t transform_err;
1857 if (current_valid(st) && st->buffer.free
1858 && transport_peers_valid(&st->peers)) {
1859 BUF_ALLOC(&st->buffer,"site:MSG7");
1860 buffer_init(&st->buffer,calculate_max_start_pad());
1861 buf_append_uint32(&st->buffer,LABEL_MSG7);
1862 buf_append_string(&st->buffer,reason);
1863 if (call_transform_forwards(st, st->current.transform,
1864 &st->buffer, &transform_err))
1866 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1867 buf_prepend_uint32(&st->buffer,st->index);
1868 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1869 transport_xmit(st,&st->peers,&st->buffer,True);
1870 BUF_FREE(&st->buffer);
1877 /* We go into this state if our peer becomes uncommunicative. Similar to
1878 the "stop" state, we forget all session keys for a while, before
1879 re-entering the "run" state. */
1880 static void enter_state_wait(struct site *st)
1882 slog(st,LOG_STATE,"entering state WAIT");
1883 st->timeout=st->now+wait_timeout(st);
1884 st->state=SITE_WAIT;
1885 set_link_quality(st);
1886 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1887 /* XXX Erase keys etc. */
1890 static void generate_prod(struct site *st, struct buffer_if *buf)
1893 buf_append_uint32(buf,0);
1894 buf_append_uint32(buf,0);
1895 buf_append_uint32(buf,LABEL_PROD);
1896 buf_append_string(buf,st->localname);
1897 buf_append_string(buf,st->remotename);
1900 static void generate_send_prod(struct site *st,
1901 const struct comm_addr *source)
1903 if (!st->allow_send_prod) return; /* too soon */
1904 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1905 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1907 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1908 st->allow_send_prod=0;
1909 generate_prod(st,&st->scratch);
1910 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1911 dump_packet(st,&st->scratch,source,False,ok);
1914 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1917 int64_t offset=timeout-*now;
1918 if (offset<0) offset=0;
1919 if (offset>INT_MAX) offset=INT_MAX;
1920 if (*timeout_io<0 || offset<*timeout_io)
1925 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1928 struct site *st=sst;
1930 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1933 /* Work out when our next timeout is. The earlier of 'timeout' or
1934 'current.key_timeout'. A stored value of '0' indicates no timeout
1936 site_settimeout(st->timeout, timeout_io);
1937 site_settimeout(st->current.key_timeout, timeout_io);
1938 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1940 return 0; /* success */
1943 static void check_expiry(struct site *st, struct data_key *key,
1946 if (key->key_timeout && *now>key->key_timeout) {
1947 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1951 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1952 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1954 struct site *st=sst;
1957 if (st->timeout && *now>st->timeout) {
1959 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1960 if (!hacky_par_start_failnow())
1962 } else if (st->state==SITE_WAIT) {
1963 enter_state_run(st);
1965 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1969 check_expiry(st,&st->current,"current key");
1970 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1973 /* This function is called by the netlink device to deliver packets
1974 intended for the remote network. The packet is in "raw" wire
1975 format, but is guaranteed to be word-aligned. */
1976 static void site_outgoing(void *sst, struct buffer_if *buf)
1978 struct site *st=sst;
1979 cstring_t transform_err;
1981 if (st->state==SITE_STOP) {
1986 st->allow_send_prod=1;
1988 /* In all other states we consider delivering the packet if we have
1989 a valid key and a valid address to send it to. */
1990 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1991 /* Transform it and send it */
1993 buf_prepend_uint32(buf,LABEL_MSG9);
1994 if (call_transform_forwards(st, st->current.transform,
1995 buf, &transform_err))
1997 buf_prepend_uint32(buf,LABEL_MSG0);
1998 buf_prepend_uint32(buf,st->index);
1999 buf_prepend_uint32(buf,st->current.remote_session_id);
2000 transport_xmit(st,&st->peers,buf,False);
2007 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
2009 initiate_key_setup(st,"outgoing packet",0);
2012 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
2013 uint32_t type, struct msg *m,
2014 struct priomsg *whynot)
2015 /* For packets which are identified by the local and remote names.
2016 * If it has our name and our peer's name in it it's for us. */
2018 struct buffer_if buf[1];
2019 buffer_readonly_clone(buf,buf_in);
2021 if (!unpick_msg(st,type,buf,m)) {
2022 priomsg_update_fixed(whynot, comm_notify_whynot_unpick, "malformed");
2025 #define NAME_MATCHES(lr) \
2026 if (!name_matches(&m->lr, st->lr##name)) { \
2027 if (priomsg_update_fixed(whynot, comm_notify_whynot_name_##lr, \
2028 "unknown " #lr " name: ")) { \
2029 truncmsg_add_packet_string(&whynot->m, m->lr.len, m->lr.name); \
2033 NAME_MATCHES(remote);
2034 NAME_MATCHES(local );
2040 static bool_t we_have_priority(struct site *st, const struct msg *m) {
2041 if (st->local_capabilities & m->remote_capabilities &
2042 CAPAB_PRIORITY_MOBILE) {
2043 if (st->local_mobile) return True;
2044 if (st-> peer_mobile) return False;
2046 return st->our_name_later;
2049 static bool_t setup_late_msg_ok(struct site *st,
2050 const struct buffer_if *buf_in,
2052 const struct comm_addr *source,
2053 struct msg *m /* returned */) {
2054 /* For setup packets which seem from their type like they are
2055 * late. Maybe they came via a different path. All we do is make
2056 * a note of the sending address, iff they look like they are part
2057 * of the current key setup attempt. */
2058 if (!named_for_us(st,buf_in,msgtype,m,0))
2059 /* named_for_us calls unpick_msg which gets the nonces */
2061 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
2062 !consttime_memeq(m->nL,st->localN, NONCELEN))
2063 /* spoof ? from stale run ? who knows */
2065 transport_setup_msgok(st,source);
2069 /* This function is called by the communication device to deliver
2070 packets from our peers.
2071 It should return True if the packet is recognised as being for
2072 this current site instance (and should therefore not be processed
2073 by other sites), even if the packet was otherwise ignored. */
2074 static bool_t site_incoming(void *sst, struct buffer_if *buf,
2075 const struct comm_addr *source,
2076 struct priomsg *whynot)
2078 struct site *st=sst;
2080 if (buf->size < 12) return False;
2082 uint32_t dest=get_uint32(buf->start);
2083 uint32_t msgtype=get_uint32(buf->start+8);
2085 /* initialised by named_for_us, or process_msgN for N!=1 */
2087 if (msgtype==LABEL_MSG1) {
2088 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2090 /* It's a MSG1 addressed to us. Decide what to do about it. */
2091 dump_packet(st,buf,source,True,True);
2092 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
2093 st->state==SITE_WAIT) {
2094 /* We should definitely process it */
2095 transport_compute_setupinit_peers(st,0,0,source);
2096 if (process_msg1(st,buf,source,&msg)) {
2097 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
2098 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
2099 if (entered && st->addresses && st->local_mobile)
2100 /* We must do this as the very last thing, because
2101 the resolver callback might reenter us. */
2102 ensure_resolving(st);
2104 slog(st,LOG_ERROR,"failed to process incoming msg1");
2108 } else if (st->state==SITE_SENTMSG1) {
2109 /* We've just sent a message 1! They may have crossed on
2110 the wire. If we have priority then we ignore the
2111 incoming one, otherwise we process it as usual. */
2112 if (we_have_priority(st,&msg)) {
2114 if (!st->msg1_crossed_logged++)
2115 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
2116 "priority => ignore incoming msg1");
2119 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
2120 "priority => use incoming msg1");
2121 if (process_msg1(st,buf,source,&msg)) {
2122 BUF_FREE(&st->buffer); /* Free our old message 1 */
2123 transport_setup_msgok(st,source);
2124 enter_new_state(st,SITE_SENTMSG2,&msg);
2126 slog(st,LOG_ERROR,"failed to process an incoming "
2127 "crossed msg1 (we have low priority)");
2132 } else if (st->state==SITE_SENTMSG2 ||
2133 st->state==SITE_SENTMSG4) {
2134 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
2135 /* We are ahead in the protocol, but that msg1 had the
2136 * peer's nonce so presumably it is from this key
2137 * exchange run, via a slower route */
2138 transport_setup_msgok(st,source);
2140 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
2145 /* The message 1 was received at an unexpected stage of the
2146 key setup. Well, they lost the race. */
2147 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
2151 if (msgtype==LABEL_PROD) {
2152 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2154 dump_packet(st,buf,source,True,True);
2155 if (st->state!=SITE_RUN) {
2156 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
2157 } else if (current_valid(st)) {
2158 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
2160 initiate_key_setup(st,"peer sent PROD packet",source);
2165 if (dest==st->index) {
2166 /* Explicitly addressed to us */
2167 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
2170 /* If the source is our current peer then initiate a key setup,
2171 because our peer's forgotten the key */
2172 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
2174 initiated = initiate_key_setup(st,"received a NAK",source);
2175 if (!initiated) generate_send_prod(st,source);
2177 slog(st,LOG_SEC,"bad incoming NAK");
2181 process_msg0(st,buf,source);
2184 /* Setup packet: should not have been explicitly addressed
2186 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2189 /* Setup packet: expected only in state SENTMSG1 */
2190 if (st->state!=SITE_SENTMSG1) {
2191 if ((st->state==SITE_SENTMSG3 ||
2192 st->state==SITE_SENTMSG5) &&
2193 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2195 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
2196 } else if (process_msg2(st,buf,source,&msg)) {
2197 transport_setup_msgok(st,source);
2198 enter_new_state(st,SITE_SENTMSG3,&msg);
2200 slog(st,LOG_SEC,"invalid MSG2");
2203 case CASES_MSG3_KNOWN:
2204 /* Setup packet: expected only in state SENTMSG2 */
2205 if (st->state!=SITE_SENTMSG2) {
2206 if ((st->state==SITE_SENTMSG4) &&
2207 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2209 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2210 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2211 transport_setup_msgok(st,source);
2212 enter_new_state(st,SITE_SENTMSG4,&msg);
2214 slog(st,LOG_SEC,"invalid MSG3");
2218 /* Setup packet: expected only in state SENTMSG3 */
2219 if (st->state!=SITE_SENTMSG3) {
2220 if ((st->state==SITE_SENTMSG5) &&
2221 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2223 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2224 } else if (process_msg4(st,buf,source,&msg)) {
2225 transport_setup_msgok(st,source);
2226 enter_new_state(st,SITE_SENTMSG5,&msg);
2228 slog(st,LOG_SEC,"invalid MSG4");
2232 /* Setup packet: expected only in state SENTMSG4 */
2233 /* (may turn up in state RUN if our return MSG6 was lost
2234 and the new key has already been activated. In that
2235 case we discard it. The peer will realise that we
2236 are using the new key when they see our data packets.
2237 Until then the peer's data packets to us get discarded. */
2238 if (st->state==SITE_SENTMSG4) {
2239 if (process_msg5(st,buf,source,st->new_transform)) {
2240 transport_setup_msgok(st,source);
2241 enter_new_state(st,SITE_RUN,&msg);
2243 slog(st,LOG_SEC,"invalid MSG5");
2245 } else if (st->state==SITE_RUN) {
2246 if (process_msg5(st,buf,source,st->current.transform)) {
2247 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2248 transport_setup_msgok(st,source);
2249 create_msg6(st,st->current.transform,
2250 st->current.remote_session_id);
2251 transport_xmit(st,&st->peers,&st->buffer,True);
2252 BUF_FREE(&st->buffer);
2254 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2257 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2261 /* Setup packet: expected only in state SENTMSG5 */
2262 if (st->state!=SITE_SENTMSG5) {
2263 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2264 } else if (process_msg6(st,buf,source)) {
2265 BUF_FREE(&st->buffer); /* Free message 5 */
2266 transport_setup_msgok(st,source);
2267 activate_new_key(st);
2269 slog(st,LOG_SEC,"invalid MSG6");
2273 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2281 priomsg_update_fixed(whynot, comm_notify_whynot_general,
2282 "not MSG1 or PROD; unknown dest index");
2286 static void site_control(void *vst, bool_t run)
2288 struct site *st=vst;
2289 if (run) enter_state_run(st);
2290 else enter_state_stop(st);
2293 static void site_phase_hook(void *sst, uint32_t newphase)
2295 struct site *st=sst;
2297 /* The program is shutting down; tell our peer */
2298 send_msg7(st,"shutting down");
2301 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2303 struct site *st=sst;
2304 dispose_transform(&st->current.transform);
2305 dispose_transform(&st->auxiliary_key.transform);
2306 dispose_transform(&st->new_transform);
2307 /* Not much point overwiting the signing key, since we loaded it
2308 from disk, and it is only valid prospectively if at all,
2310 /* XXX it would be best to overwrite the DH state, because that
2311 _is_ relevant to forward secrecy. However we have no
2312 convenient interface for doing that and in practice gmp has
2313 probably dribbled droppings all over the malloc arena. A good
2314 way to fix this would be to have a privsep child for asymmetric
2315 crypto operations, but that's a task for another day. */
2318 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2321 static uint32_t index_sequence;
2329 st->cl.description="site";
2330 st->cl.type=CL_SITE;
2332 st->cl.interface=&st->ops;
2334 st->ops.control=site_control;
2335 st->ops.status=site_status;
2336 st->peerkeys_path=0;
2337 st->peerkeys_tmpl.buffer=0;
2338 st->peerkeys_current=st->peerkeys_kex=0;
2340 /* First parameter must be a dict */
2341 item=list_elem(args,0);
2342 if (!item || item->type!=t_dict)
2343 cfgfatal(loc,"site","parameter must be a dictionary\n");
2345 dict=item->data.dict;
2346 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2347 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2348 log_event_table,"site");
2350 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2351 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2353 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2355 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2357 /* Now slog is working */
2359 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2361 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2363 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2365 /* Sanity check (which also allows the 'sites' file to include
2366 site() closures for all sites including our own): refuse to
2367 talk to ourselves */
2368 if (strcmp(st->localname,st->remotename)==0) {
2369 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2371 if (st->peer_mobile != st->local_mobile)
2372 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2373 " but our local-mobile=%d\n",
2374 st->localname, st->peer_mobile, st->local_mobile);
2378 if (st->peer_mobile && st->local_mobile) {
2379 Message(M_WARNING,"site %s: site is mobile but so are we"
2380 " -> ignoring this site\n", st->remotename);
2385 assert(index_sequence < 0xffffffffUL);
2386 st->index = ++index_sequence;
2387 st->local_capabilities = 0;
2388 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2389 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2391 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2392 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2393 if (!things##_cfg) \
2394 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2395 st->nthings=list_length(things##_cfg); \
2396 NEW_ARY(st->things,st->nthings); \
2397 assert(st->nthings); \
2398 for (i=0; i<st->nthings; i++) { \
2399 item_t *item=list_elem(things##_cfg,i); \
2400 if (item->type!=t_closure) \
2401 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2402 closure_t *cl=item->data.closure; \
2403 if (cl->type!=CL_TYPE) \
2404 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2405 st->things[i]=cl->interface; \
2409 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2411 NEW_ARY(st->commclientinfos, st->ncomms);
2412 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2413 for (i=0; i<st->ncomms; i++) {
2414 st->commclientinfos[i] =
2416 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2419 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2420 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2422 st->privkeys=find_cl_if(dict,"key-cache",CL_PRIVCACHE,False,"site",loc);
2423 if (!st->privkeys) {
2425 find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2428 struct sigpubkey_if *fixed_pubkey
2429 =find_cl_if(dict,"key",CL_SIGPUBKEY,False,"site",loc);
2430 st->peerkeys_path=dict_read_string(dict,"peer-keys",fixed_pubkey==0,
2432 if (st->peerkeys_path) {
2433 pathprefix_template_init(&st->peerkeys_tmpl,st->peerkeys_path,
2434 PEERKEYS_SUFFIX_MAXLEN + 1 /* nul */);
2435 st->peerkeys_current=keyset_load(st->peerkeys_path,
2436 &st->scratch,st->log,M_ERR);
2438 fixed_pubkey->dispose(fixed_pubkey->st);
2441 assert(fixed_pubkey);
2442 NEW(st->peerkeys_current);
2443 st->peerkeys_current->refcount=1;
2444 st->peerkeys_current->nkeys=1;
2445 st->peerkeys_current->keys[0].id=keyid_zero;
2446 st->peerkeys_current->keys[0].pubkey=fixed_pubkey;
2447 slog(st,LOG_SIGKEYS,
2448 "using old-style fixed peer public key (no `peer-keys')");
2451 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2453 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2454 else st->remoteport=0;
2456 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2458 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2460 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2461 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2462 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2464 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2465 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2466 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2467 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2468 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2470 st->mobile_peer_expiry= dict_read_number(
2471 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2473 const char *peerskey= st->peer_mobile
2474 ? "mobile-peers-max" : "static-peers-max";
2475 st->transport_peers_max= dict_read_number(
2476 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2477 if (st->transport_peers_max<1 ||
2478 st->transport_peers_max>MAX_PEER_ADDRS) {
2479 cfgfatal(loc,"site", "%s must be in range 1.."
2480 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2483 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2484 st->key_renegotiate_time=st->key_lifetime/2;
2486 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2487 st->key_renegotiate_time=dict_read_number(
2488 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2489 if (st->key_renegotiate_time > st->key_lifetime) {
2490 cfgfatal(loc,"site",
2491 "renegotiate-time must be less than key-lifetime\n");
2494 st->resolving_count=0;
2495 st->allow_send_prod=0;
2497 /* The information we expect to see in incoming messages of type 1 */
2498 /* fixme: lots of unchecked overflows here, but the results are only
2499 corrupted packets rather than undefined behaviour */
2500 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2502 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2504 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2505 BUF_ALLOC(&st->scratch,"site:scratch");
2507 /* We are interested in poll(), but only for timeouts. We don't have
2508 any fds of our own. */
2509 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2512 st->remote_capabilities=0;
2513 st->chosen_transform=0;
2514 st->current.key_timeout=0;
2515 st->auxiliary_key.key_timeout=0;
2516 transport_peers_clear(st,&st->peers);
2517 transport_peers_clear(st,&st->setup_peers);
2518 /* XXX mlock these */
2519 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2520 st->sharedsecretlen=st->sharedsecretallocd=0;
2523 #define SET_CAPBIT(bit) do { \
2524 uint32_t capflag = 1UL << (bit); \
2525 if (st->local_capabilities & capflag) \
2526 slog(st,LOG_ERROR,"capability bit" \
2527 " %d (%#"PRIx32") reused", (bit), capflag); \
2528 st->local_capabilities |= capflag; \
2531 for (i=0; i<st->ntransforms; i++)
2532 SET_CAPBIT(st->transforms[i]->capab_bit);
2536 if (st->local_mobile || st->peer_mobile)
2537 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2539 /* We need to register the remote networks with the netlink device */
2540 uint32_t netlink_mtu; /* local virtual interface mtu */
2541 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2542 if (!st->mtu_target)
2543 st->mtu_target=netlink_mtu;
2545 for (i=0; i<st->ncomms; i++)
2546 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2548 st->current.transform=0;
2549 st->auxiliary_key.transform=0;
2550 st->new_transform=0;
2551 st->auxiliary_is_new=0;
2553 enter_state_stop(st);
2555 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2556 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2558 return new_closure(&st->cl);
2561 void site_module(dict_t *dict)
2563 add_closure(dict,"site",site_apply);
2567 /***** TRANSPORT PEERS definitions *****/
2569 static void transport_peers_debug(struct site *st, transport_peers *dst,
2570 const char *didwhat,
2571 int nargs, const struct comm_addr *args,
2576 if (!(st->log_events & LOG_PEER_ADDRS))
2577 return; /* an optimisation */
2579 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2580 (dst==&st->peers ? "data" :
2581 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2582 didwhat, nargs, dst->npeers);
2584 for (i=0, argp=(void*)args;
2586 i++, (argp+=stride?stride:sizeof(*args))) {
2587 const struct comm_addr *ca=(void*)argp;
2588 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2589 i, comm_addr_to_string(ca));
2591 for (i=0; i<dst->npeers; i++) {
2592 struct timeval diff;
2593 timersub(tv_now,&dst->peers[i].last,&diff);
2594 const struct comm_addr *ca=&dst->peers[i].addr;
2595 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2596 i, comm_addr_to_string(ca),
2597 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2601 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2602 /* peers must be sorted first */
2603 if (st->local_mobile) return;
2605 int previous_peers=peers->npeers;
2606 struct timeval oldest;
2607 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2608 oldest.tv_usec = tv_now->tv_usec;
2609 while (peers->npeers>1 &&
2610 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2612 if (peers->npeers != previous_peers)
2613 transport_peers_debug(st,peers,"expire", 0,0,0);
2616 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2617 const struct comm_addr *ca,
2618 const struct timeval *tv) {
2619 /* returns false if output is full */
2622 if (peers->npeers >= st->transport_peers_max)
2625 for (search=0; search<peers->npeers; search++)
2626 if (comm_addr_equal(&peers->peers[search].addr, ca))
2629 peers->peers[peers->npeers].addr = *ca;
2630 peers->peers[peers->npeers].last = *tv;
2635 static void transport_record_peers(struct site *st, transport_peers *peers,
2636 const struct comm_addr *addrs, int naddrs,
2638 /* We add addrs into peers. The new entries end up at the front
2639 * and displace entries towards the end (perhaps even off the
2640 * end). Any existing matching entries are moved up to the front.
2642 * Caller must first call transport_peers_expire. */
2645 /* avoids debug for uninteresting updates */
2647 for (i=0; i<peers->npeers; i++) {
2648 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2649 memmove(peers->peers+1, peers->peers,
2650 sizeof(peers->peers[0]) * i);
2651 peers->peers[0].addr = addrs[0];
2652 peers->peers[0].last = *tv_now;
2658 int old_npeers=peers->npeers;
2659 transport_peer old_peers[old_npeers];
2660 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2664 for (i=0; i<naddrs; i++) {
2665 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2668 for (i=0; i<old_npeers; i++) {
2669 const transport_peer *old=&old_peers[i];
2670 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2674 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2677 static void transport_expire_record_peers(struct site *st,
2678 transport_peers *peers,
2679 const struct comm_addr *addrs,
2680 int naddrs, const char *m) {
2681 /* Convenience function */
2682 transport_peers_expire(st,peers);
2683 transport_record_peers(st,peers,addrs,naddrs,m);
2686 static bool_t transport_compute_setupinit_peers(struct site *st,
2687 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2688 int n_configured_addrs /* 0 if none or not found */,
2689 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2690 if (!n_configured_addrs && !incoming_packet_addr &&
2691 !transport_peers_valid(&st->peers))
2694 slog(st,LOG_SETUP_INIT,
2695 "using: %d configured addr(s);%s %d old peer addrs(es)",
2697 incoming_packet_addr ? " incoming packet address;" : "",
2700 /* Non-mobile peers try addresses until one is plausible. The
2701 * effect is that this code always tries first the configured
2702 * address if supplied, or otherwise the address of the incoming
2703 * PROD, or finally the existing data peer if one exists; this is
2706 transport_peers_copy(st,&st->setup_peers,&st->peers);
2707 transport_peers_expire(st,&st->setup_peers);
2709 if (incoming_packet_addr)
2710 transport_record_peers(st,&st->setup_peers,
2711 incoming_packet_addr,1, "incoming");
2713 if (n_configured_addrs)
2714 transport_record_peers(st,&st->setup_peers,
2715 configured_addrs,n_configured_addrs, "setupinit");
2717 assert(transport_peers_valid(&st->setup_peers));
2721 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2722 if (st->peer_mobile)
2723 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2725 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2726 if (st->peer_mobile)
2727 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2730 static int transport_peers_valid(transport_peers *peers) {
2731 return peers->npeers;
2733 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2735 transport_peers_debug(st,peers,"clear",0,0,0);
2737 static void transport_peers_copy(struct site *st, transport_peers *dst,
2738 const transport_peers *src) {
2739 dst->npeers=src->npeers;
2740 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2741 transport_peers_debug(st,dst,"copy",
2742 src->npeers, &src->peers->addr, sizeof(*src->peers));
2745 static void transport_resolve_complete(struct site *st,
2746 const struct comm_addr *addrs,
2748 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2750 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2754 static void transport_resolve_complete_tardy(struct site *st,
2755 const struct comm_addr *addrs,
2757 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2758 "resolved tardily");
2761 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2763 const transport_peers *inp) {
2764 /* out and in->peers may be the same region, or nonoverlapping */
2765 const transport_peer *in=inp->peers;
2767 for (slot=0; slot<inp->npeers; slot++) {
2768 if (!(mask & (1U << slot)))
2770 if (!(out==in && slot==*nout_io))
2771 COPY_OBJ(out[*nout_io], in[slot]);
2776 void transport_xmit(struct site *st, transport_peers *peers,
2777 struct buffer_if *buf, bool_t candebug) {
2779 transport_peers_expire(st, peers);
2780 unsigned failed=0; /* bitmask */
2781 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2784 for (slot=0; slot<peers->npeers; slot++) {
2785 transport_peer *peer=&peers->peers[slot];
2786 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2788 dump_packet(st, buf, &peer->addr, False, ok);
2790 failed |= 1U << slot;
2793 if (ok && !st->peer_mobile)
2796 /* Now we need to demote/delete failing addrs: if we are mobile we
2797 * merely demote them; otherwise we delete them. */
2798 if (st->local_mobile) {
2799 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2800 /* `expected' has all the failures at the end already */
2801 if (failed != expected) {
2803 transport_peer failedpeers[nfailed];
2804 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2805 assert(fslot == nfailed);
2807 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2808 assert(wslot+nfailed == peers->npeers);
2809 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2810 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2813 if (failed && peers->npeers > 1) {
2815 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2816 peers->npeers=wslot;
2817 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2822 /***** END of transport peers declarations *****/