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_init(struct site *st, transport_peers *peers);
261 static void transport_peers_clear(struct site *st, transport_peers *peers);
262 static int transport_peers_valid(transport_peers *peers);
263 static void transport_peers_copy(struct site *st, transport_peers *dst,
264 const transport_peers *src);
266 /* Record address of incoming setup packet; resp. data packet. */
267 static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
268 static void transport_data_msgok(struct site *st, const struct comm_addr *a);
270 /* Initialise the setup addresses. Called before we send the first
271 * packet in a key exchange. If we are the initiator, as a result of
272 * resolve completing (or being determined not to be relevant) or an
273 * incoming PROD; if we are the responder, as a result of the MSG1. */
274 static bool_t transport_compute_setupinit_peers(struct site *st,
275 const struct comm_addr *configured_addrs /* 0 if none or not found */,
276 int n_configured_addrs /* 0 if none or not found */,
277 const struct comm_addr *incoming_packet_addr /* 0 if none */);
279 /* Called if we are the responder in a key setup, when the resolve
280 * completes. transport_compute_setupinit_peers will hvae been called
281 * earlier. If _complete is called, we are still doing the key setup
282 * (and we should use the new values for both the rest of the key
283 * setup and the ongoing data exchange); if _tardy is called, the key
284 * setup is done (either completed or not) and only the data peers are
286 static void transport_resolve_complete(struct site *st,
287 const struct comm_addr *addrs, int naddrs);
288 static void transport_resolve_complete_tardy(struct site *st,
289 const struct comm_addr *addrs, int naddrs);
291 static void transport_xmit(struct site *st, transport_peers *peers,
292 struct buffer_if *buf, bool_t candebug);
294 /***** END of transport peers declarations *****/
298 struct transform_inst_if *transform;
299 uint64_t key_timeout; /* End of life of current key */
300 uint32_t remote_session_id;
306 /* configuration information */
310 bool_t local_mobile, peer_mobile; /* Mobile client support */
311 int32_t transport_peers_max;
312 string_t tunname; /* localname<->remotename by default, used in logs */
313 cstring_t *addresses; /* DNS name or address(es) for bootstrapping, optional */
314 int remoteport; /* Port for bootstrapping, optional */
316 struct netlink_if *netlink;
317 struct comm_if **comms;
318 struct comm_clientinfo **commclientinfos;
320 struct resolver_if *resolver;
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 buf_append_uint32(&st->buffer,st->local_capabilities);
667 if (type_is_msg34(type)) {
668 buf_append_uint16(&st->buffer,st->mtu_target);
670 if (type_is_msg23(type)) {
671 buf_append_uint8(&st->buffer,st->peerkeys_kex->nkeys);
672 for (ki=0; ki<st->peerkeys_kex->nkeys; ki++) {
673 struct peer_pubkey *pk = &st->peerkeys_kex->keys[ki];
674 BUF_ADD_OBJ(append,&st->buffer,pk->id);
677 struct sigprivkey_if *privkey=0;
678 if (type_is_msg34(type)) {
679 assert(prompt->n_pubkeys_accepted_nom>0);
681 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
683 const struct sigkeyid *kid=prompt->pubkeys_accepted[ki];
685 privkey=st->privkeys->lookup(st->privkeys->st,kid,st->log);
686 if (privkey) goto privkey_found;
688 if (sigkeyid_equal(&keyid_zero,kid)) {
689 privkey=st->privkey_fixed;
694 uint32_t class = slog_start(st,LOG_ERROR);
696 slilog_part(st->log,class,"no suitable private key, peer wanted");
698 ki<prompt->n_pubkeys_accepted_nom && ki<MAX_SIG_KEYS;
700 slilog_part(st->log,class, " " SIGKEYID_PR_FMT,
701 SIGKEYID_PR_VAL(prompt->pubkeys_accepted[ki]));
703 if (prompt->n_pubkeys_accepted_nom > MAX_SIG_KEYS)
704 slilog_part(st->log,class," +%d",
705 prompt->n_pubkeys_accepted_nom - MAX_SIG_KEYS);
706 slilog_part(st->log,class,"\n");
711 slog(st,LOG_SIGKEYS,"using private key #%d " SIGKEYID_PR_FMT,
712 ki, SIGKEYID_PR_VAL(prompt->pubkeys_accepted[ki]));
713 buf_append_uint8(&st->buffer,ki);
716 append_string_xinfo_done(&st->buffer,&xia);
718 buf_append_string(&st->buffer,st->remotename);
719 BUF_ADD_OBJ(append,&st->buffer,st->localN);
720 if (type==LABEL_MSG1) return True;
721 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
722 if (type==LABEL_MSG2) return True;
724 if (hacky_par_mid_failnow()) return False;
726 if (MSGMAJOR(type) == 3) do {
727 minor = MSGMINOR(type);
728 if (minor < 1) break;
729 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
732 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
733 buf_append_string(&st->buffer,dhpub);
736 bool_t ok=privkey->sign(privkey->st,
747 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
750 nm->len=buf_unprepend_uint16(msg);
751 CHECK_AVAIL(msg,nm->len);
752 nm->name=buf_unprepend(msg,nm->len);
753 uint8_t *nul=memchr(nm->name,0,nm->len);
755 buffer_readonly_view(&nm->extrainfo,0,0);
757 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
758 nm->len=nul-nm->name;
763 static bool_t unpick_msg(struct site *st, uint32_t type,
764 struct buffer_if *msg, struct msg *m)
768 m->n_pubkeys_accepted_nom=-1;
769 m->capab_transformnum=-1;
770 m->signing_key_index=-1;
771 m->hashstart=msg->start;
773 m->dest=buf_unprepend_uint32(msg);
775 m->source=buf_unprepend_uint32(msg);
776 CHECK_TYPE(msg,type);
777 if (!unpick_name(msg,&m->remote)) return False;
778 m->remote_capabilities=0;
780 if (m->remote.extrainfo.size) {
781 CHECK_AVAIL(&m->remote.extrainfo,4);
782 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
784 if (type_is_msg34(type) && m->remote.extrainfo.size) {
785 CHECK_AVAIL(&m->remote.extrainfo,2);
786 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
788 if (type_is_msg23(type) && m->remote.extrainfo.size) {
789 m->n_pubkeys_accepted_nom = buf_unprepend_uint8(&m->remote.extrainfo);
790 if (!m->n_pubkeys_accepted_nom) return False;
791 for (int ki_nom=0; ki_nom<m->n_pubkeys_accepted_nom; ki_nom++) {
792 CHECK_AVAIL(&m->remote.extrainfo,KEYIDSZ);
793 struct sigkeyid *kid = buf_unprepend(&m->remote.extrainfo,KEYIDSZ);
794 if (ki_nom<MAX_SIG_KEYS) m->pubkeys_accepted[ki_nom] = kid;
797 m->n_pubkeys_accepted_nom = 1;
798 m->pubkeys_accepted[0] = &keyid_zero;
800 if (type_is_msg34(type) && m->remote.extrainfo.size) {
801 m->signing_key_index=buf_unprepend_uint8(&m->remote.extrainfo);
803 m->signing_key_index=0;
805 if (!unpick_name(msg,&m->local)) return False;
806 if (type==LABEL_PROD) {
810 CHECK_AVAIL(msg,NONCELEN);
811 m->nR=buf_unprepend(msg,NONCELEN);
812 if (type==LABEL_MSG1) {
816 CHECK_AVAIL(msg,NONCELEN);
817 m->nL=buf_unprepend(msg,NONCELEN);
818 if (type==LABEL_MSG2) {
822 if (MSGMAJOR(type) == 3) do {
823 minor = MSGMINOR(type);
824 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
825 if (minor < (minminor)) \
826 m->capab_##kind##num = (dflt); \
828 CHECK_AVAIL(msg, 1); \
829 m->capab_##kind##num = buf_unprepend_uint8(msg); \
832 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
833 #undef MAYBE_READ_CAP
836 m->pklen=buf_unprepend_uint16(msg);
837 CHECK_AVAIL(msg,m->pklen);
838 m->pk=buf_unprepend(msg,m->pklen);
839 m->hashlen=msg->start-m->hashstart;
841 if (m->signing_key_index < 0 ||
842 m->signing_key_index >= st->peerkeys_kex->nkeys) {
845 struct sigpubkey_if *pubkey=
846 st->peerkeys_kex->keys[m->signing_key_index].pubkey;
847 if (!pubkey->unpick(pubkey->st,msg,&m->sig)) {
856 static bool_t name_matches(const struct parsedname *nm, const char *expected)
858 int expected_len=strlen(expected);
860 nm->len == expected_len &&
861 !memcmp(nm->name, expected, expected_len);
864 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
867 if (type==LABEL_MSG1) return True;
869 /* Check that the site names and our nonce have been sent
870 back correctly, and then store our peer's nonce. */
871 if (!name_matches(&m->remote,st->remotename)) {
872 *error="wrong remote site name";
875 if (!name_matches(&m->local,st->localname)) {
876 *error="wrong local site name";
879 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
880 *error="wrong locally-generated nonce";
883 if (type==LABEL_MSG2) return True;
884 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
885 *error="wrong remotely-generated nonce";
888 /* MSG3 has complicated rules about capabilities, which are
889 * handled in process_msg3. */
890 if (MSGMAJOR(type) == 3) return True;
891 if (m->remote_capabilities!=st->remote_capabilities) {
892 *error="remote capabilities changed";
895 if (type==LABEL_MSG4) return True;
896 *error="unknown message type";
900 static void peerkeys_maybe_incorporate(struct site *st, const char *file,
901 const char *whatmore,
904 struct peer_keyset *atsuffix=
905 keyset_load(file,&st->scratch,st->log,logcl_enoent);
906 if (!atsuffix) return;
908 if (st->peerkeys_current &&
909 serial_cmp(atsuffix->serial,st->peerkeys_current->serial) <= 0) {
910 slog(st,LOG_SIGKEYS,"keys from %s%s are older, discarding",
912 keyset_dispose(&atsuffix);
914 if (r) slog(st,LOG_ERROR,"failed to remove old key update %s: %s\n",
915 st->peerkeys_tmpl.buffer,strerror(errno));
918 slog(st,LOG_SIGKEYS,"keys from %s%s are newer, installing",
920 keyset_dispose(&st->peerkeys_current);
921 st->peerkeys_current=atsuffix;
922 int r=rename(file,st->peerkeys_path);
923 if (r) slog(st,LOG_ERROR,"failed to install key update %s as %s: %s\n",
924 st->peerkeys_tmpl.buffer,st->peerkeys_path,
929 static void peerkeys_check_for_update(struct site *st)
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 if (st->state!=SITE_STOP)
1716 slog(st,LOG_STATE,"entering state RUN%s",
1717 current_valid(st) ? " (keyed)" : " (unkeyed)");
1721 st->setup_session_id=0;
1722 transport_peers_clear(st,&st->setup_peers);
1723 keyset_dispose(&st->peerkeys_kex);
1724 FILLZERO(st->localN);
1725 FILLZERO(st->remoteN);
1726 dispose_transform(&st->new_transform);
1727 memset(st->dhsecret,0,st->dh->len);
1728 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1729 set_link_quality(st);
1731 if (st->keepalive && !current_valid(st))
1732 initiate_key_setup(st, "keepalive", 0);
1735 static bool_t ensure_resolving(struct site *st)
1737 /* Reentrancy hazard: may call site_resolve_callback and hence
1738 * enter_new_state, enter_state_* and generate_msg*. */
1739 if (st->resolving_count)
1742 assert(st->addresses);
1744 /* resolver->request might reentrantly call site_resolve_callback
1745 * which will decrement st->resolving, so we need to increment it
1746 * twice beforehand to prevent decrement from thinking we're
1747 * finished, and decrement it ourselves. Alternatively if
1748 * everything fails then there are no callbacks due and we simply
1749 * set it to 0 and return false.. */
1750 st->resolving_n_results_stored=0;
1751 st->resolving_n_results_all=0;
1752 st->resolving_count+=2;
1753 const char **addrp=st->addresses;
1754 const char *address;
1756 for (; (address=*addrp++); ) {
1757 bool_t ok = st->resolver->request(st->resolver->st,address,
1758 st->remoteport,st->comms[0],
1759 site_resolve_callback,st);
1761 st->resolving_count++;
1765 st->resolving_count=0;
1768 decrement_resolving_count(st,2);
1772 static bool_t enter_state_resolve(struct site *st)
1774 /* Reentrancy hazard! See ensure_resolving. */
1775 state_assert(st,st->state==SITE_RUN);
1776 slog(st,LOG_STATE,"entering state RESOLVE");
1777 st->state=SITE_RESOLVE;
1778 return ensure_resolving(st);
1781 static bool_t enter_new_state(struct site *st, uint32_t next,
1782 const struct msg *prompt
1783 /* may be 0 for SENTMSG1 */)
1785 bool_t (*gen)(struct site *st, const struct msg *prompt);
1788 slog(st,LOG_STATE,"entering state %s",state_name(next));
1791 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1792 if (!kex_init(st)) return False;
1794 st->msg1_crossed_logged = False;
1797 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1798 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1799 if (!kex_init(st)) return False;
1803 state_assert(st,st->state==SITE_SENTMSG1);
1804 BUF_FREE(&st->buffer);
1808 state_assert(st,st->state==SITE_SENTMSG2);
1809 BUF_FREE(&st->buffer);
1813 state_assert(st,st->state==SITE_SENTMSG3);
1814 BUF_FREE(&st->buffer);
1818 state_assert(st,st->state==SITE_SENTMSG4);
1819 BUF_FREE(&st->buffer);
1824 fatal("enter_new_state(%s): invalid new state",state_name(next));
1828 if (hacky_par_start_failnow()) return False;
1830 r= gen(st,prompt) && send_msg(st);
1833 st->setup_retries, st->setup_retry_interval,
1838 if (next==SITE_RUN) {
1839 BUF_FREE(&st->buffer); /* Never reused */
1840 st->timeout=0; /* Never retransmit */
1841 activate_new_key(st);
1845 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1846 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1847 in either state, and enter_state_wait() will
1849 enter_state_wait(st);
1853 /* msg7 tells our peer that we're about to forget our key */
1854 static bool_t send_msg7(struct site *st, cstring_t reason)
1856 cstring_t transform_err;
1858 if (current_valid(st) && st->buffer.free
1859 && transport_peers_valid(&st->peers)) {
1860 BUF_ALLOC(&st->buffer,"site:MSG7");
1861 buffer_init(&st->buffer,calculate_max_start_pad());
1862 buf_append_uint32(&st->buffer,LABEL_MSG7);
1863 buf_append_string(&st->buffer,reason);
1864 if (call_transform_forwards(st, st->current.transform,
1865 &st->buffer, &transform_err))
1867 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1868 buf_prepend_uint32(&st->buffer,st->index);
1869 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1870 transport_xmit(st,&st->peers,&st->buffer,True);
1871 BUF_FREE(&st->buffer);
1878 /* We go into this state if our peer becomes uncommunicative. Similar to
1879 the "stop" state, we forget all session keys for a while, before
1880 re-entering the "run" state. */
1881 static void enter_state_wait(struct site *st)
1883 slog(st,LOG_STATE,"entering state WAIT");
1884 st->timeout=st->now+wait_timeout(st);
1885 st->state=SITE_WAIT;
1886 set_link_quality(st);
1887 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1888 /* XXX Erase keys etc. */
1891 static void generate_prod(struct site *st, struct buffer_if *buf)
1894 buf_append_uint32(buf,0);
1895 buf_append_uint32(buf,0);
1896 buf_append_uint32(buf,LABEL_PROD);
1897 buf_append_string(buf,st->localname);
1898 buf_append_string(buf,st->remotename);
1901 static void generate_send_prod(struct site *st,
1902 const struct comm_addr *source)
1904 if (!st->allow_send_prod) return; /* too soon */
1905 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1906 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1908 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1909 st->allow_send_prod=0;
1910 generate_prod(st,&st->scratch);
1911 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1912 dump_packet(st,&st->scratch,source,False,ok);
1915 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1918 int64_t offset=timeout-*now;
1919 if (offset<0) offset=0;
1920 if (offset>INT_MAX) offset=INT_MAX;
1921 if (*timeout_io<0 || offset<*timeout_io)
1926 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1929 struct site *st=sst;
1931 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1934 /* Work out when our next timeout is. The earlier of 'timeout' or
1935 'current.key_timeout'. A stored value of '0' indicates no timeout
1937 site_settimeout(st->timeout, timeout_io);
1938 site_settimeout(st->current.key_timeout, timeout_io);
1939 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1941 return 0; /* success */
1944 static void check_expiry(struct site *st, struct data_key *key,
1947 if (key->key_timeout && *now>key->key_timeout) {
1948 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1952 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1953 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1955 struct site *st=sst;
1958 if (st->timeout && *now>st->timeout) {
1960 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1961 if (!hacky_par_start_failnow())
1963 } else if (st->state==SITE_WAIT) {
1964 enter_state_run(st);
1966 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1970 check_expiry(st,&st->current,"current key");
1971 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1974 /* This function is called by the netlink device to deliver packets
1975 intended for the remote network. The packet is in "raw" wire
1976 format, but is guaranteed to be word-aligned. */
1977 static void site_outgoing(void *sst, struct buffer_if *buf)
1979 struct site *st=sst;
1980 cstring_t transform_err;
1982 if (st->state==SITE_STOP) {
1987 st->allow_send_prod=1;
1989 /* In all other states we consider delivering the packet if we have
1990 a valid key and a valid address to send it to. */
1991 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1992 /* Transform it and send it */
1994 buf_prepend_uint32(buf,LABEL_MSG9);
1995 if (call_transform_forwards(st, st->current.transform,
1996 buf, &transform_err))
1998 buf_prepend_uint32(buf,LABEL_MSG0);
1999 buf_prepend_uint32(buf,st->index);
2000 buf_prepend_uint32(buf,st->current.remote_session_id);
2001 transport_xmit(st,&st->peers,buf,False);
2008 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
2010 initiate_key_setup(st,"outgoing packet",0);
2013 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
2014 uint32_t type, struct msg *m,
2015 struct priomsg *whynot)
2016 /* For packets which are identified by the local and remote names.
2017 * If it has our name and our peer's name in it it's for us. */
2019 struct buffer_if buf[1];
2020 buffer_readonly_clone(buf,buf_in);
2022 if (!unpick_msg(st,type,buf,m)) {
2023 priomsg_update_fixed(whynot, comm_notify_whynot_unpick, "malformed");
2026 #define NAME_MATCHES(lr) \
2027 if (!name_matches(&m->lr, st->lr##name)) { \
2028 if (priomsg_update_fixed(whynot, comm_notify_whynot_name_##lr, \
2029 "unknown " #lr " name: ")) { \
2030 truncmsg_add_packet_string(&whynot->m, m->lr.len, m->lr.name); \
2034 NAME_MATCHES(remote);
2035 NAME_MATCHES(local );
2041 static bool_t we_have_priority(struct site *st, const struct msg *m) {
2042 if (st->local_capabilities & m->remote_capabilities &
2043 CAPAB_PRIORITY_MOBILE) {
2044 if (st->local_mobile) return True;
2045 if (st-> peer_mobile) return False;
2047 return st->our_name_later;
2050 static bool_t setup_late_msg_ok(struct site *st,
2051 const struct buffer_if *buf_in,
2053 const struct comm_addr *source,
2054 struct msg *m /* returned */) {
2055 /* For setup packets which seem from their type like they are
2056 * late. Maybe they came via a different path. All we do is make
2057 * a note of the sending address, iff they look like they are part
2058 * of the current key setup attempt. */
2059 if (!named_for_us(st,buf_in,msgtype,m,0))
2060 /* named_for_us calls unpick_msg which gets the nonces */
2062 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
2063 !consttime_memeq(m->nL,st->localN, NONCELEN))
2064 /* spoof ? from stale run ? who knows */
2066 transport_setup_msgok(st,source);
2070 /* This function is called by the communication device to deliver
2071 packets from our peers.
2072 It should return True if the packet is recognised as being for
2073 this current site instance (and should therefore not be processed
2074 by other sites), even if the packet was otherwise ignored. */
2075 static bool_t site_incoming(void *sst, struct buffer_if *buf,
2076 const struct comm_addr *source,
2077 struct priomsg *whynot)
2079 struct site *st=sst;
2081 if (buf->size < 12) return False;
2083 uint32_t dest=get_uint32(buf->start);
2084 uint32_t msgtype=get_uint32(buf->start+8);
2086 /* initialised by named_for_us, or process_msgN for N!=1 */
2088 if (msgtype==LABEL_MSG1) {
2089 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2091 /* It's a MSG1 addressed to us. Decide what to do about it. */
2092 dump_packet(st,buf,source,True,True);
2093 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
2094 st->state==SITE_WAIT) {
2095 /* We should definitely process it */
2096 transport_compute_setupinit_peers(st,0,0,source);
2097 if (process_msg1(st,buf,source,&msg)) {
2098 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
2099 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
2100 if (entered && st->addresses && st->local_mobile)
2101 /* We must do this as the very last thing, because
2102 the resolver callback might reenter us. */
2103 ensure_resolving(st);
2105 slog(st,LOG_ERROR,"failed to process incoming msg1");
2109 } else if (st->state==SITE_SENTMSG1) {
2110 /* We've just sent a message 1! They may have crossed on
2111 the wire. If we have priority then we ignore the
2112 incoming one, otherwise we process it as usual. */
2113 if (we_have_priority(st,&msg)) {
2115 if (!st->msg1_crossed_logged++)
2116 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
2117 "priority => ignore incoming msg1");
2120 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
2121 "priority => use incoming msg1");
2122 if (process_msg1(st,buf,source,&msg)) {
2123 BUF_FREE(&st->buffer); /* Free our old message 1 */
2124 transport_setup_msgok(st,source);
2125 enter_new_state(st,SITE_SENTMSG2,&msg);
2127 slog(st,LOG_ERROR,"failed to process an incoming "
2128 "crossed msg1 (we have low priority)");
2133 } else if (st->state==SITE_SENTMSG2 ||
2134 st->state==SITE_SENTMSG4) {
2135 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
2136 /* We are ahead in the protocol, but that msg1 had the
2137 * peer's nonce so presumably it is from this key
2138 * exchange run, via a slower route */
2139 transport_setup_msgok(st,source);
2141 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
2146 /* The message 1 was received at an unexpected stage of the
2147 key setup. Well, they lost the race. */
2148 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
2152 if (msgtype==LABEL_PROD) {
2153 if (!named_for_us(st,buf,msgtype,&msg,whynot))
2155 dump_packet(st,buf,source,True,True);
2156 if (st->state!=SITE_RUN) {
2157 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
2158 } else if (current_valid(st)) {
2159 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
2161 initiate_key_setup(st,"peer sent PROD packet",source);
2166 if (dest==st->index) {
2167 /* Explicitly addressed to us */
2168 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
2171 /* If the source is our current peer then initiate a key setup,
2172 because our peer's forgotten the key */
2173 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
2175 initiated = initiate_key_setup(st,"received a NAK",source);
2176 if (!initiated) generate_send_prod(st,source);
2178 slog(st,LOG_SEC,"bad incoming NAK");
2182 process_msg0(st,buf,source);
2185 /* Setup packet: should not have been explicitly addressed
2187 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2190 /* Setup packet: expected only in state SENTMSG1 */
2191 if (st->state!=SITE_SENTMSG1) {
2192 if ((st->state==SITE_SENTMSG3 ||
2193 st->state==SITE_SENTMSG5) &&
2194 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2196 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
2197 } else if (process_msg2(st,buf,source,&msg)) {
2198 transport_setup_msgok(st,source);
2199 enter_new_state(st,SITE_SENTMSG3,&msg);
2201 slog(st,LOG_SEC,"invalid MSG2");
2204 case CASES_MSG3_KNOWN:
2205 /* Setup packet: expected only in state SENTMSG2 */
2206 if (st->state!=SITE_SENTMSG2) {
2207 if ((st->state==SITE_SENTMSG4) &&
2208 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2210 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2211 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2212 transport_setup_msgok(st,source);
2213 enter_new_state(st,SITE_SENTMSG4,&msg);
2215 slog(st,LOG_SEC,"invalid MSG3");
2219 /* Setup packet: expected only in state SENTMSG3 */
2220 if (st->state!=SITE_SENTMSG3) {
2221 if ((st->state==SITE_SENTMSG5) &&
2222 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2224 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2225 } else if (process_msg4(st,buf,source,&msg)) {
2226 transport_setup_msgok(st,source);
2227 enter_new_state(st,SITE_SENTMSG5,&msg);
2229 slog(st,LOG_SEC,"invalid MSG4");
2233 /* Setup packet: expected only in state SENTMSG4 */
2234 /* (may turn up in state RUN if our return MSG6 was lost
2235 and the new key has already been activated. In that
2236 case we discard it. The peer will realise that we
2237 are using the new key when they see our data packets.
2238 Until then the peer's data packets to us get discarded. */
2239 if (st->state==SITE_SENTMSG4) {
2240 if (process_msg5(st,buf,source,st->new_transform)) {
2241 transport_setup_msgok(st,source);
2242 enter_new_state(st,SITE_RUN,&msg);
2244 slog(st,LOG_SEC,"invalid MSG5");
2246 } else if (st->state==SITE_RUN) {
2247 if (process_msg5(st,buf,source,st->current.transform)) {
2248 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2249 transport_setup_msgok(st,source);
2250 create_msg6(st,st->current.transform,
2251 st->current.remote_session_id);
2252 transport_xmit(st,&st->peers,&st->buffer,True);
2253 BUF_FREE(&st->buffer);
2255 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2258 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2262 /* Setup packet: expected only in state SENTMSG5 */
2263 if (st->state!=SITE_SENTMSG5) {
2264 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2265 } else if (process_msg6(st,buf,source)) {
2266 BUF_FREE(&st->buffer); /* Free message 5 */
2267 transport_setup_msgok(st,source);
2268 activate_new_key(st);
2270 slog(st,LOG_SEC,"invalid MSG6");
2274 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2282 priomsg_update_fixed(whynot, comm_notify_whynot_general,
2283 "not MSG1 or PROD; unknown dest index");
2287 static void site_startup(void *vst)
2289 struct site *st=vst;
2290 enter_state_run(st);
2293 static void site_phase_shutdown_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_phase_run_hook(void *sst, uint32_t newphase)
2303 struct site *st=sst;
2304 slog(st,LOG_STATE,"entering phase RUN in state %s",
2305 state_name(st->state));
2308 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2310 struct site *st=sst;
2311 dispose_transform(&st->current.transform);
2312 dispose_transform(&st->auxiliary_key.transform);
2313 dispose_transform(&st->new_transform);
2314 /* Not much point overwiting the signing key, since we loaded it
2315 from disk, and it is only valid prospectively if at all,
2317 /* XXX it would be best to overwrite the DH state, because that
2318 _is_ relevant to forward secrecy. However we have no
2319 convenient interface for doing that and in practice gmp has
2320 probably dribbled droppings all over the malloc arena. A good
2321 way to fix this would be to have a privsep child for asymmetric
2322 crypto operations, but that's a task for another day. */
2325 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2328 static uint32_t index_sequence;
2336 st->cl.description="site";
2337 st->cl.type=CL_SITE;
2339 st->cl.interface=&st->ops;
2341 st->ops.startup=site_startup;
2342 st->ops.status=site_status;
2343 st->peerkeys_path=0;
2344 st->peerkeys_tmpl.buffer=0;
2345 st->peerkeys_current=st->peerkeys_kex=0;
2347 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2348 BUF_ALLOC(&st->scratch,"site:scratch");
2350 /* First parameter must be a dict */
2351 item=list_elem(args,0);
2352 if (!item || item->type!=t_dict)
2353 cfgfatal(loc,"site","parameter must be a dictionary\n");
2355 dict=item->data.dict;
2356 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2357 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2358 log_event_table,"site");
2360 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2361 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2363 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2365 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2367 /* Now slog is working */
2369 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2371 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2373 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2375 /* Sanity check (which also allows the 'sites' file to include
2376 site() closures for all sites including our own): refuse to
2377 talk to ourselves */
2378 if (strcmp(st->localname,st->remotename)==0) {
2379 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2381 if (st->peer_mobile != st->local_mobile)
2382 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2383 " but our local-mobile=%d\n",
2384 st->localname, st->peer_mobile, st->local_mobile);
2388 if (st->peer_mobile && st->local_mobile) {
2389 Message(M_WARNING,"site %s: site is mobile but so are we"
2390 " -> ignoring this site\n", st->remotename);
2395 assert(index_sequence < 0xffffffffUL);
2396 st->index = ++index_sequence;
2397 st->local_capabilities = 0;
2398 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2399 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2401 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2402 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2403 if (!things##_cfg) \
2404 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2405 st->nthings=list_length(things##_cfg); \
2406 NEW_ARY(st->things,st->nthings); \
2407 assert(st->nthings); \
2408 for (i=0; i<st->nthings; i++) { \
2409 item_t *item=list_elem(things##_cfg,i); \
2410 if (item->type!=t_closure) \
2411 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2412 closure_t *cl=item->data.closure; \
2413 if (cl->type!=CL_TYPE) \
2414 cfgfatal_cl_type(loc,"site",cl,CL_TYPE,dictkey); \
2415 st->things[i]=cl->interface; \
2419 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2421 NEW_ARY(st->commclientinfos, st->ncomms);
2422 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2423 for (i=0; i<st->ncomms; i++) {
2424 st->commclientinfos[i] =
2426 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2429 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2430 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2432 st->privkeys=find_cl_if(dict,"key-cache",CL_PRIVCACHE,False,"site",loc);
2433 if (!st->privkeys) {
2435 find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2438 struct sigpubkey_if *fixed_pubkey
2439 =find_cl_if(dict,"key",CL_SIGPUBKEY,False,"site",loc);
2440 st->peerkeys_path=dict_read_string(dict,"peer-keys",fixed_pubkey==0,
2442 if (st->peerkeys_path) {
2443 pathprefix_template_init(&st->peerkeys_tmpl,st->peerkeys_path,
2444 PEERKEYS_SUFFIX_MAXLEN + 1 /* nul */);
2445 st->peerkeys_current=keyset_load(st->peerkeys_path,
2446 &st->scratch,st->log,M_ERR);
2448 fixed_pubkey->dispose(fixed_pubkey->st);
2451 assert(fixed_pubkey);
2452 NEW(st->peerkeys_current);
2453 st->peerkeys_current->refcount=1;
2454 st->peerkeys_current->nkeys=1;
2455 st->peerkeys_current->keys[0].id=keyid_zero;
2456 st->peerkeys_current->keys[0].pubkey=fixed_pubkey;
2457 slog(st,LOG_SIGKEYS,
2458 "using old-style fixed peer public key (no `peer-keys')");
2461 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2463 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2464 else st->remoteport=0;
2466 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2468 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2470 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2471 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2472 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2474 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2475 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2476 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2477 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2478 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2480 st->mobile_peer_expiry= dict_read_number(
2481 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2483 const char *peerskey= st->peer_mobile
2484 ? "mobile-peers-max" : "static-peers-max";
2485 st->transport_peers_max= dict_read_number(
2486 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2487 if (st->transport_peers_max<1 ||
2488 st->transport_peers_max>MAX_PEER_ADDRS) {
2489 cfgfatal(loc,"site", "%s must be in range 1.."
2490 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2493 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2494 st->key_renegotiate_time=st->key_lifetime/2;
2496 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2497 st->key_renegotiate_time=dict_read_number(
2498 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2499 if (st->key_renegotiate_time > st->key_lifetime) {
2500 cfgfatal(loc,"site",
2501 "renegotiate-time must be less than key-lifetime\n");
2504 st->resolving_count=0;
2505 st->allow_send_prod=0;
2507 /* The information we expect to see in incoming messages of type 1 */
2508 /* fixme: lots of unchecked overflows here, but the results are only
2509 corrupted packets rather than undefined behaviour */
2510 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2512 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2514 /* We are interested in poll(), but only for timeouts. We don't have
2515 any fds of our own. */
2516 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2519 st->remote_capabilities=0;
2520 st->chosen_transform=0;
2521 st->current.key_timeout=0;
2522 st->auxiliary_key.key_timeout=0;
2523 transport_peers_init(st,&st->peers);
2524 transport_peers_init(st,&st->setup_peers);
2525 /* XXX mlock these */
2526 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2527 st->sharedsecretlen=st->sharedsecretallocd=0;
2530 #define SET_CAPBIT(bit) do { \
2531 uint32_t capflag = 1UL << (bit); \
2532 if (st->local_capabilities & capflag) \
2533 slog(st,LOG_ERROR,"capability bit" \
2534 " %d (%#"PRIx32") reused", (bit), capflag); \
2535 st->local_capabilities |= capflag; \
2538 for (i=0; i<st->ntransforms; i++)
2539 SET_CAPBIT(st->transforms[i]->capab_bit);
2543 if (st->local_mobile || st->peer_mobile)
2544 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2546 /* We need to register the remote networks with the netlink device */
2547 uint32_t netlink_mtu; /* local virtual interface mtu */
2548 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2549 if (!st->mtu_target)
2550 st->mtu_target=netlink_mtu;
2552 for (i=0; i<st->ncomms; i++)
2553 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2555 st->current.transform=0;
2556 st->auxiliary_key.transform=0;
2557 st->new_transform=0;
2558 st->auxiliary_is_new=0;
2560 enter_state_stop(st);
2562 add_hook(PHASE_SHUTDOWN,site_phase_shutdown_hook,st);
2563 add_hook(PHASE_RUN, site_phase_run_hook, st);
2564 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2566 return new_closure(&st->cl);
2569 void site_module(dict_t *dict)
2571 add_closure(dict,"site",site_apply);
2575 /***** TRANSPORT PEERS definitions *****/
2577 static void transport_peers_debug(struct site *st, transport_peers *dst,
2578 const char *didwhat,
2579 int nargs, const struct comm_addr *args,
2584 if (!(st->log_events & LOG_PEER_ADDRS))
2585 return; /* an optimisation */
2587 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2588 (dst==&st->peers ? "data" :
2589 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2590 didwhat, nargs, dst->npeers);
2592 for (i=0, argp=(void*)args;
2594 i++, (argp+=stride?stride:sizeof(*args))) {
2595 const struct comm_addr *ca=(void*)argp;
2596 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2597 i, comm_addr_to_string(ca));
2599 for (i=0; i<dst->npeers; i++) {
2600 struct timeval diff;
2601 timersub(tv_now,&dst->peers[i].last,&diff);
2602 const struct comm_addr *ca=&dst->peers[i].addr;
2603 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2604 i, comm_addr_to_string(ca),
2605 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2609 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2610 /* peers must be sorted first */
2611 if (st->local_mobile) return;
2613 int previous_peers=peers->npeers;
2614 struct timeval oldest;
2615 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2616 oldest.tv_usec = tv_now->tv_usec;
2617 while (peers->npeers>1 &&
2618 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2620 if (peers->npeers != previous_peers)
2621 transport_peers_debug(st,peers,"expire", 0,0,0);
2624 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2625 const struct comm_addr *ca,
2626 const struct timeval *tv) {
2627 /* returns false if output is full */
2630 if (peers->npeers >= st->transport_peers_max)
2633 for (search=0; search<peers->npeers; search++)
2634 if (comm_addr_equal(&peers->peers[search].addr, ca))
2637 peers->peers[peers->npeers].addr = *ca;
2638 peers->peers[peers->npeers].last = *tv;
2643 static void transport_record_peers(struct site *st, transport_peers *peers,
2644 const struct comm_addr *addrs, int naddrs,
2646 /* We add addrs into peers. The new entries end up at the front
2647 * and displace entries towards the end (perhaps even off the
2648 * end). Any existing matching entries are moved up to the front.
2650 * Caller must first call transport_peers_expire. */
2653 /* avoids debug for uninteresting updates */
2655 for (i=0; i<peers->npeers; i++) {
2656 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2657 memmove(peers->peers+1, peers->peers,
2658 sizeof(peers->peers[0]) * i);
2659 peers->peers[0].addr = addrs[0];
2660 peers->peers[0].last = *tv_now;
2666 int old_npeers=peers->npeers;
2667 transport_peer old_peers[old_npeers];
2668 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2672 for (i=0; i<naddrs; i++) {
2673 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2676 for (i=0; i<old_npeers; i++) {
2677 const transport_peer *old=&old_peers[i];
2678 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2682 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2685 static void transport_expire_record_peers(struct site *st,
2686 transport_peers *peers,
2687 const struct comm_addr *addrs,
2688 int naddrs, const char *m) {
2689 /* Convenience function */
2690 transport_peers_expire(st,peers);
2691 transport_record_peers(st,peers,addrs,naddrs,m);
2694 static bool_t transport_compute_setupinit_peers(struct site *st,
2695 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2696 int n_configured_addrs /* 0 if none or not found */,
2697 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2698 if (!n_configured_addrs && !incoming_packet_addr &&
2699 !transport_peers_valid(&st->peers))
2702 slog(st,LOG_SETUP_INIT,
2703 "using: %d configured addr(s);%s %d old peer addrs(es)",
2705 incoming_packet_addr ? " incoming packet address;" : "",
2708 /* Non-mobile peers try addresses until one is plausible. The
2709 * effect is that this code always tries first the configured
2710 * address if supplied, or otherwise the address of the incoming
2711 * PROD, or finally the existing data peer if one exists; this is
2714 transport_peers_copy(st,&st->setup_peers,&st->peers);
2715 transport_peers_expire(st,&st->setup_peers);
2717 if (incoming_packet_addr)
2718 transport_record_peers(st,&st->setup_peers,
2719 incoming_packet_addr,1, "incoming");
2721 if (n_configured_addrs)
2722 transport_record_peers(st,&st->setup_peers,
2723 configured_addrs,n_configured_addrs, "setupinit");
2725 assert(transport_peers_valid(&st->setup_peers));
2729 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2730 if (st->peer_mobile)
2731 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2733 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2734 if (st->peer_mobile)
2735 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2738 static int transport_peers_valid(transport_peers *peers) {
2739 return peers->npeers;
2741 static void transport_peers_init(struct site *st, transport_peers *peers) {
2744 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2745 bool_t need_debug=!!peers->npeers;
2748 transport_peers_debug(st,peers,"clear",0,0,0);
2750 static void transport_peers_copy(struct site *st, transport_peers *dst,
2751 const transport_peers *src) {
2752 dst->npeers=src->npeers;
2753 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2754 transport_peers_debug(st,dst,"copy",
2755 src->npeers, &src->peers->addr, sizeof(*src->peers));
2758 static void transport_resolve_complete(struct site *st,
2759 const struct comm_addr *addrs,
2761 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2763 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2767 static void transport_resolve_complete_tardy(struct site *st,
2768 const struct comm_addr *addrs,
2770 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2771 "resolved tardily");
2774 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2776 const transport_peers *inp) {
2777 /* out and in->peers may be the same region, or nonoverlapping */
2778 const transport_peer *in=inp->peers;
2780 for (slot=0; slot<inp->npeers; slot++) {
2781 if (!(mask & (1U << slot)))
2783 if (!(out==in && slot==*nout_io))
2784 COPY_OBJ(out[*nout_io], in[slot]);
2789 void transport_xmit(struct site *st, transport_peers *peers,
2790 struct buffer_if *buf, bool_t candebug) {
2792 transport_peers_expire(st, peers);
2793 unsigned failed=0; /* bitmask */
2794 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2797 for (slot=0; slot<peers->npeers; slot++) {
2798 transport_peer *peer=&peers->peers[slot];
2799 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2801 dump_packet(st, buf, &peer->addr, False, ok);
2803 failed |= 1U << slot;
2806 if (ok && !st->peer_mobile)
2809 /* Now we need to demote/delete failing addrs: if we are mobile we
2810 * merely demote them; otherwise we delete them. */
2811 if (st->local_mobile) {
2812 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2813 /* `expected' has all the failures at the end already */
2814 if (failed != expected) {
2816 transport_peer failedpeers[nfailed];
2817 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2818 assert(fslot == nfailed);
2820 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2821 assert(wslot+nfailed == peers->npeers);
2822 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2823 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2826 if (failed && peers->npeers > 1) {
2828 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2829 peers->npeers=wslot;
2830 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2835 /***** END of transport peers declarations *****/