Commit | Line | Data |
---|---|---|
2fe58dfd SE |
1 | /* site.c - manage communication with a remote network site */ |
2 | ||
469fd1d9 SE |
3 | /* The 'site' code doesn't know anything about the structure of the |
4 | packets it's transmitting. In fact, under the new netlink | |
5 | configuration scheme it doesn't need to know anything at all about | |
6 | IP addresses, except how to contact its peer. This means it could | |
7 | potentially be used to tunnel other protocols too (IPv6, IPX, plain | |
8 | old Ethernet frames) if appropriate netlink code can be written | |
9 | (and that ought not to be too hard, eg. using the TUN/TAP device to | |
10 | pretend to be an Ethernet interface). */ | |
11 | ||
ff05a229 SE |
12 | /* At some point in the future the netlink code will be asked for |
13 | configuration information to go in the PING/PONG packets at the end | |
14 | of the key exchange. */ | |
15 | ||
8689b3a9 | 16 | #include "secnet.h" |
2fe58dfd | 17 | #include <stdio.h> |
469fd1d9 | 18 | #include <string.h> |
8689b3a9 | 19 | #include <sys/socket.h> |
2fe58dfd | 20 | |
8689b3a9 | 21 | #include <sys/mman.h> |
2fe58dfd | 22 | #include "util.h" |
59635212 | 23 | #include "unaligned.h" |
ff05a229 | 24 | #include "magic.h" |
2fe58dfd SE |
25 | |
26 | #define SETUP_BUFFER_LEN 2048 | |
27 | ||
9d3a4132 SE |
28 | #define DEFAULT_KEY_LIFETIME 3600000 /* One hour */ |
29 | #define DEFAULT_KEY_RENEGOTIATE_GAP 300000 /* Five minutes */ | |
2fe58dfd | 30 | #define DEFAULT_SETUP_RETRIES 5 |
4f5e39ec | 31 | #define DEFAULT_SETUP_TIMEOUT 2000 |
3454dce4 | 32 | #define DEFAULT_WAIT_TIME 20000 |
2fe58dfd SE |
33 | |
34 | /* Each site can be in one of several possible states. */ | |
35 | ||
36 | /* States: | |
37 | SITE_STOP - nothing is allowed to happen; tunnel is down; | |
38 | all session keys have been erased | |
39 | -> SITE_RUN upon external instruction | |
40 | SITE_RUN - site up, maybe with valid key | |
41 | -> SITE_RESOLVE upon outgoing packet and no valid key | |
42 | we start name resolution for the other end of the tunnel | |
43 | -> SITE_SENTMSG2 upon valid incoming message 1 and suitable time | |
44 | we send an appropriate message 2 | |
45 | SITE_RESOLVE - waiting for name resolution | |
46 | -> SITE_SENTMSG1 upon successful resolution | |
47 | we send an appropriate message 1 | |
48 | -> SITE_SENTMSG2 upon valid incoming message 1 (then abort resolution) | |
49 | we abort resolution and | |
50 | -> SITE_WAIT on timeout or resolution failure | |
51 | SITE_SENTMSG1 | |
52 | -> SITE_SENTMSG2 upon valid incoming message 1 from higher priority end | |
53 | -> SITE_SENTMSG3 upon valid incoming message 2 | |
54 | -> SITE_WAIT on timeout | |
55 | SITE_SENTMSG2 | |
56 | -> SITE_SENTMSG4 upon valid incoming message 3 | |
57 | -> SITE_WAIT on timeout | |
58 | SITE_SENTMSG3 | |
59 | -> SITE_SENTMSG5 upon valid incoming message 4 | |
60 | -> SITE_WAIT on timeout | |
61 | SITE_SENTMSG4 | |
62 | -> SITE_RUN upon valid incoming message 5 | |
63 | -> SITE_WAIT on timeout | |
64 | SITE_SENTMSG5 | |
65 | -> SITE_RUN upon valid incoming message 6 | |
66 | -> SITE_WAIT on timeout | |
67 | SITE_WAIT - failed to establish key; do nothing for a while | |
68 | -> SITE_RUN on timeout | |
69 | */ | |
70 | ||
71 | #define SITE_STOP 0 | |
72 | #define SITE_RUN 1 | |
73 | #define SITE_RESOLVE 2 | |
74 | #define SITE_SENTMSG1 3 | |
75 | #define SITE_SENTMSG2 4 | |
76 | #define SITE_SENTMSG3 5 | |
77 | #define SITE_SENTMSG4 6 | |
78 | #define SITE_SENTMSG5 7 | |
79 | #define SITE_WAIT 8 | |
80 | ||
81 | static string_t state_name(uint32_t state) | |
82 | { | |
83 | switch (state) { | |
3454dce4 SE |
84 | case 0: return "STOP"; |
85 | case 1: return "RUN"; | |
86 | case 2: return "RESOLVE"; | |
87 | case 3: return "SENTMSG1"; | |
88 | case 4: return "SENTMSG2"; | |
89 | case 5: return "SENTMSG3"; | |
90 | case 6: return "SENTMSG4"; | |
91 | case 7: return "SENTMSG5"; | |
92 | case 8: return "WAIT"; | |
2fe58dfd SE |
93 | default: return "*bad state*"; |
94 | } | |
95 | } | |
96 | ||
2fe58dfd SE |
97 | #define NONCELEN 8 |
98 | ||
99 | #define LOG_UNEXPECTED 0x00000001 | |
100 | #define LOG_SETUP_INIT 0x00000002 | |
101 | #define LOG_SETUP_TIMEOUT 0x00000004 | |
102 | #define LOG_ACTIVATE_KEY 0x00000008 | |
103 | #define LOG_TIMEOUT_KEY 0x00000010 | |
9d3a4132 | 104 | #define LOG_SEC 0x00000020 |
2fe58dfd SE |
105 | #define LOG_STATE 0x00000040 |
106 | #define LOG_DROP 0x00000080 | |
107 | #define LOG_DUMP 0x00000100 | |
108 | #define LOG_ERROR 0x00000400 | |
109 | ||
9d3a4132 SE |
110 | static struct flagstr log_event_table[]={ |
111 | { "unexpected", LOG_UNEXPECTED }, | |
112 | { "setup-init", LOG_SETUP_INIT }, | |
113 | { "setup-timeout", LOG_SETUP_TIMEOUT }, | |
114 | { "activate-key", LOG_ACTIVATE_KEY }, | |
115 | { "timeout-key", LOG_TIMEOUT_KEY }, | |
116 | { "security", LOG_SEC }, | |
117 | { "state-change", LOG_STATE }, | |
118 | { "packet-drop", LOG_DROP }, | |
119 | { "dump-packets", LOG_DUMP }, | |
120 | { "errors", LOG_ERROR }, | |
ff05a229 SE |
121 | { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT| |
122 | LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR }, | |
9d3a4132 SE |
123 | { "all", 0xffffffff }, |
124 | { NULL, 0 } | |
125 | }; | |
126 | ||
2fe58dfd SE |
127 | struct site { |
128 | closure_t cl; | |
129 | struct site_if ops; | |
130 | /* configuration information */ | |
131 | string_t localname; | |
132 | string_t remotename; | |
ff05a229 | 133 | string_t tunname; /* localname<->remotename by default, used in logs */ |
2fe58dfd | 134 | string_t address; /* DNS name for bootstrapping, optional */ |
ff05a229 | 135 | int remoteport; /* Port for bootstrapping, optional */ |
2fe58dfd SE |
136 | struct netlink_if *netlink; |
137 | struct comm_if *comm; | |
138 | struct resolver_if *resolver; | |
139 | struct log_if *log; | |
140 | struct random_if *random; | |
141 | struct rsaprivkey_if *privkey; | |
2fe58dfd SE |
142 | struct rsapubkey_if *pubkey; |
143 | struct transform_if *transform; | |
144 | struct dh_if *dh; | |
145 | struct hash_if *hash; | |
2fe58dfd SE |
146 | |
147 | uint32_t setup_retries; /* How many times to send setup packets */ | |
148 | uint32_t setup_timeout; /* Initial timeout for setup packets */ | |
149 | uint32_t wait_timeout; /* How long to wait if setup unsuccessful */ | |
150 | uint32_t key_lifetime; /* How long a key lasts once set up */ | |
9d3a4132 SE |
151 | uint32_t key_renegotiate_time; /* If we see traffic (or a keepalive) |
152 | after this time, initiate a new | |
153 | key exchange */ | |
ff05a229 SE |
154 | bool_t keepalive; /* Send keepalives to detect peer failure (not yet |
155 | implemented) */ | |
2fe58dfd SE |
156 | |
157 | uint8_t *setupsig; /* Expected signature of incoming MSG1 packets */ | |
158 | uint32_t setupsiglen; /* Allows us to discard packets quickly if | |
159 | they are not for us */ | |
160 | bool_t setup_priority; /* Do we have precedence if both sites emit | |
161 | message 1 simultaneously? */ | |
162 | uint32_t log_events; | |
163 | ||
164 | /* runtime information */ | |
165 | uint32_t state; | |
166 | uint64_t now; /* Most recently seen time */ | |
167 | ||
ff05a229 | 168 | /* The currently established session */ |
2fe58dfd SE |
169 | uint32_t remote_session_id; |
170 | struct transform_inst_if *current_transform; | |
171 | bool_t current_valid; | |
172 | uint64_t current_key_timeout; /* End of life of current key */ | |
ff05a229 | 173 | uint64_t renegotiate_key_time; /* When we can negotiate a new key */ |
2fe58dfd SE |
174 | struct sockaddr_in peer; /* Current address of peer */ |
175 | bool_t peer_valid; /* Peer address becomes invalid when key times out, | |
176 | but only if we have a DNS name for our peer */ | |
177 | ||
ff05a229 SE |
178 | /* The current key setup protocol exchange. We can only be |
179 | involved in one of these at a time. There's a potential for | |
180 | denial of service here (the attacker keeps sending a setup | |
181 | packet; we keep trying to continue the exchange, and have to | |
182 | timeout before we can listen for another setup packet); perhaps | |
183 | we should keep a list of 'bad' sources for setup packets. */ | |
2fe58dfd SE |
184 | uint32_t setup_session_id; |
185 | struct sockaddr_in setup_peer; | |
186 | uint8_t localN[NONCELEN]; /* Nonces for key exchange */ | |
187 | uint8_t remoteN[NONCELEN]; | |
188 | struct buffer_if buffer; /* Current outgoing key exchange packet */ | |
189 | uint32_t retries; /* Number of retries remaining */ | |
190 | uint64_t timeout; /* Timeout for current state */ | |
191 | uint8_t *dhsecret; | |
192 | uint8_t *sharedsecret; | |
2fe58dfd SE |
193 | struct transform_inst_if *new_transform; /* For key setup/verify */ |
194 | }; | |
195 | ||
196 | static void slog(struct site *st, uint32_t event, string_t msg, ...) | |
197 | { | |
198 | va_list ap; | |
199 | uint8_t buf[240]; | |
b2a56f7c | 200 | uint32_t class; |
2fe58dfd SE |
201 | |
202 | va_start(ap,msg); | |
203 | ||
204 | if (event&st->log_events) { | |
b2a56f7c SE |
205 | switch(event) { |
206 | case LOG_UNEXPECTED: class=M_INFO; break; | |
207 | case LOG_SETUP_INIT: class=M_INFO; break; | |
208 | case LOG_SETUP_TIMEOUT: class=M_NOTICE; break; | |
209 | case LOG_ACTIVATE_KEY: class=M_INFO; break; | |
210 | case LOG_TIMEOUT_KEY: class=M_INFO; break; | |
211 | case LOG_SEC: class=M_SECURITY; break; | |
212 | case LOG_STATE: class=M_DEBUG; break; | |
213 | case LOG_DROP: class=M_DEBUG; break; | |
214 | case LOG_DUMP: class=M_DEBUG; break; | |
469fd1d9 SE |
215 | case LOG_ERROR: class=M_ERR; break; |
216 | default: class=M_ERR; break; | |
b2a56f7c SE |
217 | } |
218 | ||
2fe58dfd | 219 | vsnprintf(buf,240,msg,ap); |
b2a56f7c | 220 | st->log->log(st->log->st,class,"%s: %s",st->tunname,buf); |
2fe58dfd SE |
221 | } |
222 | va_end(ap); | |
223 | } | |
224 | ||
9d3a4132 | 225 | static void set_link_quality(struct site *st); |
794f2398 SE |
226 | static void delete_key(struct site *st, string_t reason, uint32_t loglevel); |
227 | static bool_t initiate_key_setup(struct site *st, string_t reason); | |
2fe58dfd SE |
228 | static void enter_state_run(struct site *st); |
229 | static bool_t enter_state_resolve(struct site *st); | |
ff05a229 | 230 | static bool_t enter_new_state(struct site *st,uint32_t next); |
2fe58dfd SE |
231 | static void enter_state_wait(struct site *st); |
232 | ||
233 | #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0) | |
234 | #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0) | |
235 | #define CHECK_TYPE(b,t) do { uint32_t type; \ | |
236 | CHECK_AVAIL((b),4); \ | |
59635212 | 237 | type=buf_unprepend_uint32((b)); \ |
2fe58dfd SE |
238 | if (type!=(t)) return False; } while(0) |
239 | ||
240 | struct msg { | |
241 | uint8_t *hashstart; | |
242 | uint32_t dest; | |
243 | uint32_t source; | |
244 | uint32_t remlen; | |
245 | uint8_t *remote; | |
246 | uint32_t loclen; | |
247 | uint8_t *local; | |
248 | uint8_t *nR; | |
249 | uint8_t *nL; | |
250 | uint32_t pklen; | |
251 | uint8_t *pk; | |
252 | uint32_t hashlen; | |
253 | uint32_t siglen; | |
254 | uint8_t *sig; | |
255 | }; | |
256 | ||
ff05a229 SE |
257 | /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside |
258 | out using a transform of config data supplied by netlink */ | |
2fe58dfd SE |
259 | static bool_t generate_msg(struct site *st, uint32_t type, string_t what) |
260 | { | |
261 | void *hst; | |
262 | uint8_t *hash=alloca(st->hash->len); | |
263 | string_t dhpub, sig; | |
264 | ||
265 | st->retries=st->setup_retries; | |
266 | BUF_ALLOC(&st->buffer,what); | |
267 | buffer_init(&st->buffer,0); | |
59635212 SE |
268 | buf_append_uint32(&st->buffer, |
269 | (type==LABEL_MSG1?0:st->setup_session_id)); | |
270 | buf_append_uint32(&st->buffer,(uint32_t)st); | |
271 | buf_append_uint32(&st->buffer,type); | |
2fe58dfd SE |
272 | buf_append_string(&st->buffer,st->localname); |
273 | buf_append_string(&st->buffer,st->remotename); | |
274 | memcpy(buf_append(&st->buffer,NONCELEN),st->localN,NONCELEN); | |
275 | if (type==LABEL_MSG1) return True; | |
276 | memcpy(buf_append(&st->buffer,NONCELEN),st->remoteN,NONCELEN); | |
277 | if (type==LABEL_MSG2) return True; | |
278 | dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len); | |
279 | buf_append_string(&st->buffer,dhpub); | |
280 | free(dhpub); | |
281 | hst=st->hash->init(); | |
282 | st->hash->update(hst,st->buffer.start,st->buffer.size); | |
283 | st->hash->final(hst,hash); | |
284 | sig=st->privkey->sign(st->privkey->st,hash,st->hash->len); | |
285 | buf_append_string(&st->buffer,sig); | |
286 | free(sig); | |
287 | return True; | |
288 | } | |
289 | ||
290 | static bool_t unpick_msg(struct site *st, uint32_t type, | |
291 | struct buffer_if *msg, struct msg *m) | |
292 | { | |
293 | m->hashstart=msg->start; | |
294 | CHECK_AVAIL(msg,4); | |
59635212 | 295 | m->dest=buf_unprepend_uint32(msg); |
2fe58dfd | 296 | CHECK_AVAIL(msg,4); |
59635212 | 297 | m->source=buf_unprepend_uint32(msg); |
2fe58dfd SE |
298 | CHECK_TYPE(msg,type); |
299 | CHECK_AVAIL(msg,2); | |
59635212 | 300 | m->remlen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
301 | CHECK_AVAIL(msg,m->remlen); |
302 | m->remote=buf_unprepend(msg,m->remlen); | |
303 | CHECK_AVAIL(msg,2); | |
59635212 | 304 | m->loclen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
305 | CHECK_AVAIL(msg,m->loclen); |
306 | m->local=buf_unprepend(msg,m->loclen); | |
307 | CHECK_AVAIL(msg,NONCELEN); | |
308 | m->nR=buf_unprepend(msg,NONCELEN); | |
309 | if (type==LABEL_MSG1) { | |
310 | CHECK_EMPTY(msg); | |
311 | return True; | |
312 | } | |
313 | CHECK_AVAIL(msg,NONCELEN); | |
314 | m->nL=buf_unprepend(msg,NONCELEN); | |
315 | if (type==LABEL_MSG2) { | |
316 | CHECK_EMPTY(msg); | |
317 | return True; | |
318 | } | |
319 | CHECK_AVAIL(msg,2); | |
59635212 | 320 | m->pklen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
321 | CHECK_AVAIL(msg,m->pklen); |
322 | m->pk=buf_unprepend(msg,m->pklen); | |
323 | m->hashlen=msg->start-m->hashstart; | |
324 | CHECK_AVAIL(msg,2); | |
59635212 | 325 | m->siglen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
326 | CHECK_AVAIL(msg,m->siglen); |
327 | m->sig=buf_unprepend(msg,m->siglen); | |
328 | CHECK_EMPTY(msg); | |
329 | return True; | |
330 | } | |
331 | ||
ff05a229 SE |
332 | static bool_t check_msg(struct site *st, uint32_t type, struct msg *m, |
333 | string_t *error) | |
334 | { | |
335 | if (type==LABEL_MSG1) return True; | |
336 | ||
337 | /* Check that the site names and our nonce have been sent | |
338 | back correctly, and then store our peer's nonce. */ | |
339 | if (memcmp(m->remote,st->remotename,strlen(st->remotename)!=0)) { | |
340 | *error="wrong remote site name"; | |
341 | return False; | |
342 | } | |
343 | if (memcmp(m->local,st->localname,strlen(st->localname)!=0)) { | |
344 | *error="wrong local site name"; | |
345 | return False; | |
346 | } | |
347 | if (memcmp(m->nL,st->localN,NONCELEN)!=0) { | |
348 | *error="wrong locally-generated nonce"; | |
349 | return False; | |
350 | } | |
351 | if (type==LABEL_MSG2) return True; | |
352 | if (memcmp(m->nR,st->remoteN,NONCELEN)!=0) { | |
353 | *error="wrong remotely-generated nonce"; | |
354 | return False; | |
355 | } | |
356 | if (type==LABEL_MSG3) return True; | |
357 | if (type==LABEL_MSG4) return True; | |
358 | *error="unknown message type"; | |
359 | return False; | |
360 | } | |
361 | ||
2fe58dfd SE |
362 | static bool_t generate_msg1(struct site *st) |
363 | { | |
364 | st->random->generate(st->random->st,NONCELEN,st->localN); | |
365 | return generate_msg(st,LABEL_MSG1,"site:MSG1"); | |
366 | } | |
367 | ||
368 | static bool_t process_msg1(struct site *st, struct buffer_if *msg1, | |
369 | struct sockaddr_in *src) | |
370 | { | |
371 | struct msg m; | |
372 | ||
373 | /* We've already determined we're in an appropriate state to | |
374 | process an incoming MSG1, and that the MSG1 has correct values | |
375 | of A and B. */ | |
376 | ||
377 | if (!unpick_msg(st,LABEL_MSG1,msg1,&m)) return False; | |
378 | ||
2fe58dfd | 379 | st->setup_peer=*src; |
2fe58dfd SE |
380 | st->setup_session_id=m.source; |
381 | memcpy(st->remoteN,m.nR,NONCELEN); | |
382 | return True; | |
383 | } | |
384 | ||
385 | static bool_t generate_msg2(struct site *st) | |
386 | { | |
387 | st->random->generate(st->random->st,NONCELEN,st->localN); | |
388 | return generate_msg(st,LABEL_MSG2,"site:MSG2"); | |
389 | } | |
390 | ||
391 | static bool_t process_msg2(struct site *st, struct buffer_if *msg2, | |
392 | struct sockaddr_in *src) | |
393 | { | |
394 | struct msg m; | |
ff05a229 | 395 | string_t err; |
2fe58dfd SE |
396 | |
397 | if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False; | |
ff05a229 SE |
398 | if (!check_msg(st,LABEL_MSG2,&m,&err)) { |
399 | slog(st,LOG_SEC,"msg2: %s",err); | |
2fe58dfd SE |
400 | return False; |
401 | } | |
402 | st->setup_session_id=m.source; | |
403 | memcpy(st->remoteN,m.nR,NONCELEN); | |
404 | return True; | |
405 | } | |
406 | ||
407 | static bool_t generate_msg3(struct site *st) | |
408 | { | |
409 | /* Now we have our nonce and their nonce. Think of a secret key, | |
410 | and create message number 3. */ | |
411 | st->random->generate(st->random->st,st->dh->len,st->dhsecret); | |
412 | return generate_msg(st,LABEL_MSG3,"site:MSG3"); | |
413 | } | |
414 | ||
415 | static bool_t process_msg3(struct site *st, struct buffer_if *msg3, | |
416 | struct sockaddr_in *src) | |
417 | { | |
418 | struct msg m; | |
419 | uint8_t *hash=alloca(st->hash->len); | |
420 | void *hst; | |
ff05a229 | 421 | string_t err; |
2fe58dfd SE |
422 | |
423 | if (!unpick_msg(st,LABEL_MSG3,msg3,&m)) return False; | |
ff05a229 SE |
424 | if (!check_msg(st,LABEL_MSG3,&m,&err)) { |
425 | slog(st,LOG_SEC,"msg3: %s",err); | |
2fe58dfd SE |
426 | return False; |
427 | } | |
ff05a229 | 428 | |
2fe58dfd SE |
429 | /* Check signature and store g^x mod m */ |
430 | hst=st->hash->init(); | |
431 | st->hash->update(hst,m.hashstart,m.hashlen); | |
432 | st->hash->final(hst,hash); | |
433 | /* Terminate signature with a '0' - cheating, but should be ok */ | |
434 | m.sig[m.siglen]=0; | |
435 | if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) { | |
59635212 | 436 | slog(st,LOG_SEC,"msg3 signature failed check!"); |
2fe58dfd SE |
437 | return False; |
438 | } | |
439 | ||
440 | /* Terminate their DH public key with a '0' */ | |
441 | m.pk[m.pklen]=0; | |
442 | /* Invent our DH secret key */ | |
443 | st->random->generate(st->random->st,st->dh->len,st->dhsecret); | |
444 | ||
445 | /* Generate the shared key */ | |
446 | st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,m.pk, | |
447 | st->sharedsecret,st->transform->keylen); | |
448 | ||
449 | /* Set up the transform */ | |
450 | st->new_transform->setkey(st->new_transform->st,st->sharedsecret, | |
451 | st->transform->keylen); | |
452 | ||
453 | return True; | |
454 | } | |
455 | ||
456 | static bool_t generate_msg4(struct site *st) | |
457 | { | |
458 | /* We have both nonces, their public key and our private key. Generate | |
459 | our public key, sign it and send it to them. */ | |
460 | return generate_msg(st,LABEL_MSG4,"site:MSG4"); | |
461 | } | |
462 | ||
463 | static bool_t process_msg4(struct site *st, struct buffer_if *msg4, | |
464 | struct sockaddr_in *src) | |
465 | { | |
466 | struct msg m; | |
467 | uint8_t *hash=alloca(st->hash->len); | |
468 | void *hst; | |
ff05a229 | 469 | string_t err; |
2fe58dfd SE |
470 | |
471 | if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False; | |
ff05a229 SE |
472 | if (!check_msg(st,LABEL_MSG4,&m,&err)) { |
473 | slog(st,LOG_SEC,"msg4: %s",err); | |
2fe58dfd SE |
474 | return False; |
475 | } | |
476 | ||
477 | /* Check signature and store g^x mod m */ | |
478 | hst=st->hash->init(); | |
479 | st->hash->update(hst,m.hashstart,m.hashlen); | |
480 | st->hash->final(hst,hash); | |
481 | /* Terminate signature with a '0' - cheating, but should be ok */ | |
482 | m.sig[m.siglen]=0; | |
483 | if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) { | |
59635212 | 484 | slog(st,LOG_SEC,"msg4 signature failed check!"); |
2fe58dfd SE |
485 | return False; |
486 | } | |
487 | ||
488 | /* Terminate their DH public key with a '0' */ | |
489 | m.pk[m.pklen]=0; | |
490 | /* Generate the shared key */ | |
491 | st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,m.pk, | |
492 | st->sharedsecret,st->transform->keylen); | |
493 | /* Set up the transform */ | |
494 | st->new_transform->setkey(st->new_transform->st,st->sharedsecret, | |
495 | st->transform->keylen); | |
496 | ||
497 | return True; | |
498 | } | |
499 | ||
2fe58dfd SE |
500 | struct msg0 { |
501 | uint32_t dest; | |
502 | uint32_t source; | |
503 | uint32_t type; | |
504 | }; | |
505 | ||
506 | static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0, | |
507 | struct msg0 *m) | |
508 | { | |
509 | CHECK_AVAIL(msg0,4); | |
59635212 | 510 | m->dest=buf_unprepend_uint32(msg0); |
2fe58dfd | 511 | CHECK_AVAIL(msg0,4); |
59635212 | 512 | m->source=buf_unprepend_uint32(msg0); |
2fe58dfd | 513 | CHECK_AVAIL(msg0,4); |
59635212 | 514 | m->type=buf_unprepend_uint32(msg0); |
2fe58dfd SE |
515 | return True; |
516 | /* Leaves transformed part of buffer untouched */ | |
517 | } | |
518 | ||
ff05a229 SE |
519 | static bool_t generate_msg5(struct site *st) |
520 | { | |
521 | string_t transform_err; | |
522 | ||
523 | BUF_ALLOC(&st->buffer,"site:MSG5"); | |
524 | /* We are going to add four words to the message */ | |
525 | buffer_init(&st->buffer,st->transform->max_start_pad+(4*4)); | |
526 | /* Give the netlink code an opportunity to put its own stuff in the | |
527 | message (configuration information, etc.) */ | |
528 | st->netlink->output_config(st->netlink->st,&st->buffer); | |
529 | buf_prepend_uint32(&st->buffer,LABEL_MSG5); | |
530 | st->new_transform->forwards(st->new_transform->st,&st->buffer, | |
531 | &transform_err); | |
532 | buf_prepend_uint32(&st->buffer,LABEL_MSG5); | |
533 | buf_prepend_uint32(&st->buffer,(uint32_t)st); | |
534 | buf_prepend_uint32(&st->buffer,st->setup_session_id); | |
535 | ||
536 | st->retries=st->setup_retries; | |
537 | return True; | |
538 | } | |
539 | ||
2fe58dfd SE |
540 | static bool_t process_msg5(struct site *st, struct buffer_if *msg5, |
541 | struct sockaddr_in *src) | |
542 | { | |
543 | struct msg0 m; | |
544 | string_t transform_err; | |
545 | ||
546 | if (!unpick_msg0(st,msg5,&m)) return False; | |
547 | ||
548 | if (st->new_transform->reverse(st->new_transform->st, | |
549 | msg5,&transform_err)) { | |
550 | /* There's a problem */ | |
59635212 | 551 | slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err); |
2fe58dfd SE |
552 | return False; |
553 | } | |
554 | /* Buffer should now contain untransformed PING packet data */ | |
555 | CHECK_AVAIL(msg5,4); | |
59635212 | 556 | if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) { |
ff05a229 | 557 | slog(st,LOG_SEC,"MSG5/PING packet contained wrong label"); |
2fe58dfd SE |
558 | return False; |
559 | } | |
794f2398 SE |
560 | if (!st->netlink->check_config(st->netlink->st,msg5)) { |
561 | slog(st,LOG_SEC,"MSG5/PING packet contained bad netlink config"); | |
562 | return False; | |
563 | } | |
2fe58dfd SE |
564 | CHECK_EMPTY(msg5); |
565 | return True; | |
566 | } | |
567 | ||
568 | static bool_t generate_msg6(struct site *st) | |
569 | { | |
570 | string_t transform_err; | |
571 | ||
572 | BUF_ALLOC(&st->buffer,"site:MSG6"); | |
ff05a229 SE |
573 | /* We are going to add four words to the message */ |
574 | buffer_init(&st->buffer,st->transform->max_start_pad+(4*4)); | |
794f2398 SE |
575 | /* Give the netlink code an opportunity to put its own stuff in the |
576 | message (configuration information, etc.) */ | |
577 | st->netlink->output_config(st->netlink->st,&st->buffer); | |
ff05a229 | 578 | buf_prepend_uint32(&st->buffer,LABEL_MSG6); |
2fe58dfd SE |
579 | st->new_transform->forwards(st->new_transform->st,&st->buffer, |
580 | &transform_err); | |
59635212 SE |
581 | buf_prepend_uint32(&st->buffer,LABEL_MSG6); |
582 | buf_prepend_uint32(&st->buffer,(uint32_t)st); | |
583 | buf_prepend_uint32(&st->buffer,st->setup_session_id); | |
2fe58dfd | 584 | |
ff05a229 | 585 | st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */ |
2fe58dfd SE |
586 | return True; |
587 | } | |
588 | ||
589 | static bool_t process_msg6(struct site *st, struct buffer_if *msg6, | |
590 | struct sockaddr_in *src) | |
591 | { | |
592 | struct msg0 m; | |
593 | string_t transform_err; | |
594 | ||
595 | if (!unpick_msg0(st,msg6,&m)) return False; | |
596 | ||
597 | if (st->new_transform->reverse(st->new_transform->st, | |
598 | msg6,&transform_err)) { | |
599 | /* There's a problem */ | |
59635212 | 600 | slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err); |
2fe58dfd SE |
601 | return False; |
602 | } | |
603 | /* Buffer should now contain untransformed PING packet data */ | |
604 | CHECK_AVAIL(msg6,4); | |
59635212 SE |
605 | if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) { |
606 | slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data"); | |
2fe58dfd SE |
607 | return False; |
608 | } | |
794f2398 SE |
609 | if (!st->netlink->check_config(st->netlink->st,msg6)) { |
610 | slog(st,LOG_SEC,"MSG6/PONG packet contained bad netlink config"); | |
611 | return False; | |
612 | } | |
2fe58dfd SE |
613 | CHECK_EMPTY(msg6); |
614 | return True; | |
615 | } | |
616 | ||
617 | static bool_t process_msg0(struct site *st, struct buffer_if *msg0, | |
618 | struct sockaddr_in *src) | |
619 | { | |
620 | struct msg0 m; | |
621 | string_t transform_err; | |
622 | uint32_t type; | |
623 | ||
624 | if (!st->current_valid) { | |
625 | slog(st,LOG_DROP,"incoming message but no current key -> dropping"); | |
794f2398 | 626 | return initiate_key_setup(st,"incoming message but no current key"); |
2fe58dfd SE |
627 | } |
628 | ||
629 | if (!unpick_msg0(st,msg0,&m)) return False; | |
630 | ||
631 | if (st->current_transform->reverse(st->current_transform->st, | |
632 | msg0,&transform_err)) { | |
633 | /* There's a problem */ | |
59635212 | 634 | slog(st,LOG_SEC,"transform: %s",transform_err); |
794f2398 | 635 | return initiate_key_setup(st,"incoming message would not decrypt"); |
2fe58dfd SE |
636 | } |
637 | CHECK_AVAIL(msg0,4); | |
59635212 | 638 | type=buf_unprepend_uint32(msg0); |
2fe58dfd | 639 | switch(type) { |
794f2398 SE |
640 | case LABEL_MSG7: |
641 | /* We must forget about the current session. */ | |
642 | delete_key(st,"request from peer",LOG_SEC); | |
643 | return True; | |
644 | break; | |
2fe58dfd SE |
645 | case LABEL_MSG9: |
646 | /* Deliver to netlink layer */ | |
469fd1d9 | 647 | st->netlink->deliver(st->netlink->st,msg0); |
2fe58dfd SE |
648 | return True; |
649 | break; | |
650 | default: | |
ff05a229 SE |
651 | slog(st,LOG_SEC,"incoming encrypted message of type %08x " |
652 | "(unknown)",type); | |
2fe58dfd SE |
653 | break; |
654 | } | |
655 | return False; | |
656 | } | |
657 | ||
658 | static void dump_packet(struct site *st, struct buffer_if *buf, | |
659 | struct sockaddr_in *addr, bool_t incoming) | |
660 | { | |
59635212 SE |
661 | uint32_t dest=ntohl(*(uint32_t *)buf->start); |
662 | uint32_t source=ntohl(*(uint32_t *)(buf->start+4)); | |
663 | uint32_t msgtype=ntohl(*(uint32_t *)(buf->start+8)); | |
2fe58dfd SE |
664 | |
665 | if (st->log_events & LOG_DUMP) | |
b2a56f7c | 666 | log(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:", |
9d3a4132 | 667 | st->tunname,incoming?"incoming":"outgoing", |
2fe58dfd SE |
668 | dest,source,msgtype); |
669 | } | |
670 | ||
671 | static uint32_t site_status(void *st) | |
672 | { | |
673 | return 0; | |
674 | } | |
675 | ||
676 | static bool_t send_msg(struct site *st) | |
677 | { | |
678 | if (st->retries>0) { | |
679 | dump_packet(st,&st->buffer,&st->setup_peer,False); | |
680 | st->comm->sendmsg(st->comm->st,&st->buffer,&st->setup_peer); | |
681 | st->timeout=st->now+st->setup_timeout; | |
682 | st->retries--; | |
683 | return True; | |
684 | } else { | |
3454dce4 SE |
685 | slog(st,LOG_SETUP_TIMEOUT,"timed out sending key setup packet " |
686 | "(in state %s)",state_name(st->state)); | |
2fe58dfd SE |
687 | enter_state_wait(st); |
688 | return False; | |
689 | } | |
690 | } | |
691 | ||
692 | static void site_resolve_callback(void *sst, struct in_addr *address) | |
693 | { | |
694 | struct site *st=sst; | |
695 | ||
696 | if (st->state!=SITE_RESOLVE) { | |
697 | slog(st,LOG_UNEXPECTED,"site_resolve_callback called unexpectedly"); | |
698 | return; | |
699 | } | |
700 | if (address) { | |
701 | memset(&st->setup_peer,0,sizeof(st->setup_peer)); | |
702 | st->setup_peer.sin_family=AF_INET; | |
703 | st->setup_peer.sin_port=htons(st->remoteport); | |
704 | st->setup_peer.sin_addr=*address; | |
ff05a229 | 705 | enter_new_state(st,SITE_SENTMSG1); |
2fe58dfd SE |
706 | } else { |
707 | /* Resolution failed */ | |
708 | slog(st,LOG_ERROR,"resolution of %s failed",st->address); | |
709 | enter_state_run(st); | |
710 | } | |
711 | } | |
712 | ||
794f2398 | 713 | static bool_t initiate_key_setup(struct site *st,string_t reason) |
9d3a4132 SE |
714 | { |
715 | if (st->state!=SITE_RUN) return False; | |
794f2398 | 716 | slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason); |
9d3a4132 | 717 | if (st->address) { |
794f2398 | 718 | slog(st,LOG_SETUP_INIT,"resolving peer address"); |
9d3a4132 SE |
719 | return enter_state_resolve(st); |
720 | } else if (st->peer_valid) { | |
794f2398 | 721 | slog(st,LOG_SETUP_INIT,"using old peer address"); |
9d3a4132 | 722 | st->setup_peer=st->peer; |
ff05a229 | 723 | return enter_new_state(st,SITE_SENTMSG1); |
9d3a4132 | 724 | } |
ff05a229 | 725 | slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer"); |
9d3a4132 SE |
726 | return False; |
727 | } | |
728 | ||
2fe58dfd SE |
729 | static void activate_new_key(struct site *st) |
730 | { | |
731 | struct transform_inst_if *t; | |
732 | ||
ff05a229 SE |
733 | /* We have two transform instances, which we swap between active |
734 | and setup */ | |
2fe58dfd SE |
735 | t=st->current_transform; |
736 | st->current_transform=st->new_transform; | |
737 | st->new_transform=t; | |
738 | ||
739 | t->delkey(t->st); | |
2fe58dfd SE |
740 | st->timeout=0; |
741 | st->current_valid=True; | |
742 | st->current_key_timeout=st->now+st->key_lifetime; | |
ff05a229 | 743 | st->renegotiate_key_time=st->now+st->key_renegotiate_time; |
2fe58dfd SE |
744 | st->peer=st->setup_peer; |
745 | st->peer_valid=True; | |
746 | st->remote_session_id=st->setup_session_id; | |
747 | ||
748 | slog(st,LOG_ACTIVATE_KEY,"new key activated"); | |
9d3a4132 | 749 | enter_state_run(st); |
2fe58dfd SE |
750 | } |
751 | ||
794f2398 SE |
752 | static void delete_key(struct site *st, string_t reason, uint32_t loglevel) |
753 | { | |
754 | if (st->current_valid) { | |
755 | slog(st,loglevel,"session closed (%s)",reason); | |
756 | ||
757 | st->current_valid=False; | |
758 | st->current_transform->delkey(st->current_transform->st); | |
759 | st->current_key_timeout=0; | |
760 | set_link_quality(st); | |
761 | } | |
762 | } | |
763 | ||
2fe58dfd SE |
764 | static void state_assert(struct site *st, bool_t ok) |
765 | { | |
4f5e39ec | 766 | if (!ok) fatal("site:state_assert"); |
2fe58dfd SE |
767 | } |
768 | ||
769 | static void enter_state_stop(struct site *st) | |
770 | { | |
771 | st->state=SITE_STOP; | |
772 | st->timeout=0; | |
794f2398 | 773 | delete_key(st,"entering state STOP",LOG_TIMEOUT_KEY); |
2fe58dfd SE |
774 | st->new_transform->delkey(st->new_transform->st); |
775 | } | |
776 | ||
9d3a4132 SE |
777 | static void set_link_quality(struct site *st) |
778 | { | |
779 | uint32_t quality; | |
780 | if (st->current_valid) | |
781 | quality=LINK_QUALITY_UP; | |
782 | else if (st->state==SITE_WAIT || st->state==SITE_STOP) | |
783 | quality=LINK_QUALITY_DOWN; | |
784 | else if (st->address) | |
785 | quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS; | |
786 | else if (st->peer_valid) | |
787 | quality=LINK_QUALITY_DOWN_STALE_ADDRESS; | |
788 | else | |
789 | quality=LINK_QUALITY_DOWN; | |
790 | ||
469fd1d9 | 791 | st->netlink->set_quality(st->netlink->st,quality); |
9d3a4132 SE |
792 | } |
793 | ||
2fe58dfd SE |
794 | static void enter_state_run(struct site *st) |
795 | { | |
796 | slog(st,LOG_STATE,"entering state RUN"); | |
797 | st->state=SITE_RUN; | |
798 | st->timeout=0; | |
9d3a4132 | 799 | |
ff05a229 SE |
800 | st->setup_session_id=0; |
801 | memset(&st->setup_peer,0,sizeof(st->setup_peer)); | |
802 | memset(st->localN,0,NONCELEN); | |
803 | memset(st->remoteN,0,NONCELEN); | |
804 | st->new_transform->delkey(st->new_transform->st); | |
805 | memset(st->dhsecret,0,st->dh->len); | |
806 | memset(st->sharedsecret,0,st->transform->keylen); | |
9d3a4132 | 807 | set_link_quality(st); |
2fe58dfd SE |
808 | } |
809 | ||
810 | static bool_t enter_state_resolve(struct site *st) | |
811 | { | |
812 | state_assert(st,st->state==SITE_RUN); | |
813 | slog(st,LOG_STATE,"entering state RESOLVE"); | |
814 | st->state=SITE_RESOLVE; | |
815 | st->resolver->request(st->resolver->st,st->address, | |
816 | site_resolve_callback,st); | |
817 | return True; | |
818 | } | |
819 | ||
ff05a229 | 820 | static bool_t enter_new_state(struct site *st, uint32_t next) |
2fe58dfd | 821 | { |
ff05a229 SE |
822 | bool_t (*gen)(struct site *st); |
823 | slog(st,LOG_STATE,"entering state %s",state_name(next)); | |
824 | switch(next) { | |
825 | case SITE_SENTMSG1: | |
826 | state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE); | |
827 | gen=generate_msg1; | |
828 | break; | |
829 | case SITE_SENTMSG2: | |
830 | state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE || | |
831 | st->state==SITE_SENTMSG1 || st->state==SITE_WAIT); | |
832 | gen=generate_msg2; | |
833 | break; | |
834 | case SITE_SENTMSG3: | |
835 | state_assert(st,st->state==SITE_SENTMSG1); | |
836 | BUF_FREE(&st->buffer); | |
837 | gen=generate_msg3; | |
838 | break; | |
839 | case SITE_SENTMSG4: | |
840 | state_assert(st,st->state==SITE_SENTMSG2); | |
841 | BUF_FREE(&st->buffer); | |
842 | gen=generate_msg4; | |
843 | break; | |
844 | case SITE_SENTMSG5: | |
845 | state_assert(st,st->state==SITE_SENTMSG3); | |
846 | BUF_FREE(&st->buffer); | |
847 | gen=generate_msg5; | |
848 | break; | |
849 | case SITE_RUN: | |
850 | state_assert(st,st->state==SITE_SENTMSG4); | |
851 | BUF_FREE(&st->buffer); | |
852 | gen=generate_msg6; | |
853 | break; | |
854 | default: | |
855 | gen=NULL; | |
4f5e39ec | 856 | fatal("enter_new_state(%s): invalid new state",state_name(next)); |
ff05a229 | 857 | break; |
2fe58dfd | 858 | } |
2fe58dfd | 859 | |
ff05a229 SE |
860 | if (gen(st) && send_msg(st)) { |
861 | st->state=next; | |
862 | if (next==SITE_RUN) { | |
863 | BUF_FREE(&st->buffer); /* Never reused */ | |
864 | st->timeout=0; /* Never retransmit */ | |
865 | activate_new_key(st); | |
866 | } | |
2fe58dfd SE |
867 | return True; |
868 | } | |
ff05a229 SE |
869 | slog(st,LOG_ERROR,"error entering state %s",state_name(next)); |
870 | st->buffer.free=False; /* Unconditionally use the buffer; it may be | |
871 | in either state, and enter_state_wait() will | |
872 | do a BUF_FREE() */ | |
2fe58dfd SE |
873 | enter_state_wait(st); |
874 | return False; | |
875 | } | |
876 | ||
ff05a229 | 877 | /* msg7 tells our peer that we're about to forget our key */ |
794f2398 SE |
878 | static bool_t send_msg7(struct site *st,string_t reason) |
879 | { | |
880 | string_t transform_err; | |
881 | ||
882 | if (st->current_valid && st->peer_valid && st->buffer.free) { | |
883 | BUF_ALLOC(&st->buffer,"site:MSG7"); | |
884 | buffer_init(&st->buffer,st->transform->max_start_pad+(4*3)); | |
885 | buf_append_uint32(&st->buffer,LABEL_MSG7); | |
886 | buf_append_string(&st->buffer,reason); | |
887 | st->current_transform->forwards(st->current_transform->st, | |
888 | &st->buffer, &transform_err); | |
889 | buf_prepend_uint32(&st->buffer,LABEL_MSG0); | |
890 | buf_prepend_uint32(&st->buffer,(uint32_t)st); | |
891 | buf_prepend_uint32(&st->buffer,st->remote_session_id); | |
892 | st->comm->sendmsg(st->comm->st,&st->buffer,&st->peer); | |
893 | BUF_FREE(&st->buffer); | |
894 | return True; | |
895 | } | |
896 | return False; | |
897 | } | |
898 | ||
2fe58dfd SE |
899 | /* We go into this state if our peer becomes uncommunicative. Similar to |
900 | the "stop" state, we forget all session keys for a while, before | |
901 | re-entering the "run" state. */ | |
902 | static void enter_state_wait(struct site *st) | |
903 | { | |
904 | slog(st,LOG_STATE,"entering state WAIT"); | |
905 | st->timeout=st->now+st->wait_timeout; | |
906 | st->state=SITE_WAIT; | |
907 | st->peer_valid=False; | |
9d3a4132 | 908 | set_link_quality(st); |
2fe58dfd SE |
909 | BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */ |
910 | /* XXX Erase keys etc. */ | |
911 | } | |
912 | ||
913 | static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io, | |
914 | int *timeout_io, const struct timeval *tv_now, | |
915 | uint64_t *now) | |
916 | { | |
917 | struct site *st=sst; | |
918 | ||
919 | *nfds_io=0; /* We don't use any file descriptors */ | |
920 | st->now=*now; | |
921 | ||
922 | /* Work out when our next timeout is. The earlier of 'timeout' or | |
923 | 'current_key_timeout'. A stored value of '0' indicates no timeout | |
924 | active. */ | |
925 | if (st->timeout && st->timeout-*now < *timeout_io) { | |
926 | *timeout_io=st->timeout-*now; | |
927 | } | |
928 | ||
929 | if (st->current_key_timeout && st->current_key_timeout-*now < *timeout_io) | |
930 | *timeout_io=st->current_key_timeout-*now; | |
931 | ||
932 | return 0; /* success */ | |
933 | } | |
934 | ||
935 | /* NB site_afterpoll will be called before site_beforepoll is ever called */ | |
936 | static void site_afterpoll(void *sst, struct pollfd *fds, int nfds, | |
937 | const struct timeval *tv_now, uint64_t *now) | |
938 | { | |
939 | struct site *st=sst; | |
940 | ||
941 | st->now=*now; | |
942 | if (st->timeout && *now>st->timeout) { | |
2fe58dfd SE |
943 | st->timeout=0; |
944 | if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) | |
945 | send_msg(st); | |
946 | else if (st->state==SITE_WAIT) { | |
947 | enter_state_run(st); | |
948 | } else { | |
949 | slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d", | |
950 | st->state); | |
951 | } | |
952 | } | |
953 | if (st->current_key_timeout && *now>st->current_key_timeout) { | |
794f2398 | 954 | delete_key(st,"maximum key life exceeded",LOG_TIMEOUT_KEY); |
2fe58dfd SE |
955 | } |
956 | } | |
957 | ||
958 | /* This function is called by the netlink device to deliver packets | |
959 | intended for the remote network. The packet is in "raw" wire | |
960 | format, but is guaranteed to be word-aligned. */ | |
469fd1d9 | 961 | static void site_outgoing(void *sst, struct buffer_if *buf) |
2fe58dfd SE |
962 | { |
963 | struct site *st=sst; | |
964 | string_t transform_err; | |
965 | ||
966 | if (st->state==SITE_STOP) { | |
967 | BUF_FREE(buf); | |
968 | return; | |
969 | } | |
970 | ||
971 | /* In all other states we consider delivering the packet if we have | |
972 | a valid key and a valid address to send it to. */ | |
973 | if (st->current_valid && st->peer_valid) { | |
974 | /* Transform it and send it */ | |
70dc107b SE |
975 | if (buf->size>0) { |
976 | buf_prepend_uint32(buf,LABEL_MSG9); | |
977 | st->current_transform->forwards(st->current_transform->st, | |
978 | buf, &transform_err); | |
979 | buf_prepend_uint32(buf,LABEL_MSG0); | |
980 | buf_prepend_uint32(buf,(uint32_t)st); | |
981 | buf_prepend_uint32(buf,st->remote_session_id); | |
982 | st->comm->sendmsg(st->comm->st,buf,&st->peer); | |
983 | } | |
2fe58dfd | 984 | BUF_FREE(buf); |
ff05a229 SE |
985 | /* See whether we should start negotiating a new key */ |
986 | if (st->now > st->renegotiate_key_time) | |
987 | initiate_key_setup(st,"outgoing packet in renegotiation window"); | |
2fe58dfd SE |
988 | return; |
989 | } | |
990 | ||
70dc107b | 991 | slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size); |
2fe58dfd | 992 | BUF_FREE(buf); |
794f2398 | 993 | initiate_key_setup(st,"outgoing packet"); |
2fe58dfd SE |
994 | } |
995 | ||
996 | /* This function is called by the communication device to deliver | |
997 | packets from our peers. */ | |
998 | static bool_t site_incoming(void *sst, struct buffer_if *buf, | |
999 | struct sockaddr_in *source) | |
1000 | { | |
1001 | struct site *st=sst; | |
59635212 | 1002 | uint32_t dest=ntohl(*(uint32_t *)buf->start); |
2fe58dfd SE |
1003 | |
1004 | if (dest==0) { | |
2fe58dfd SE |
1005 | /* It could be for any site - it should have LABEL_MSG1 and |
1006 | might have our name and our peer's name in it */ | |
ff05a229 | 1007 | if (buf->size<(st->setupsiglen+8+NONCELEN)) return False; |
2fe58dfd | 1008 | if (memcmp(buf->start+8,st->setupsig,st->setupsiglen)==0) { |
2fe58dfd | 1009 | /* It's addressed to us. Decide what to do about it. */ |
ff05a229 | 1010 | dump_packet(st,buf,source,True); |
2fe58dfd SE |
1011 | if (st->state==SITE_RUN || st->state==SITE_RESOLVE || |
1012 | st->state==SITE_WAIT) { | |
1013 | /* We should definitely process it */ | |
1014 | if (process_msg1(st,buf,source)) { | |
1015 | slog(st,LOG_SETUP_INIT,"key setup initiated by peer"); | |
ff05a229 | 1016 | enter_new_state(st,SITE_SENTMSG2); |
2fe58dfd SE |
1017 | } else { |
1018 | slog(st,LOG_ERROR,"failed to process incoming msg1"); | |
1019 | } | |
1020 | BUF_FREE(buf); | |
1021 | return True; | |
ff05a229 | 1022 | } else if (st->state==SITE_SENTMSG1) { |
2fe58dfd SE |
1023 | /* We've just sent a message 1! They may have crossed on |
1024 | the wire. If we have priority then we ignore the | |
1025 | incoming one, otherwise we process it as usual. */ | |
1026 | if (st->setup_priority) { | |
1027 | BUF_FREE(buf); | |
1028 | slog(st,LOG_DUMP,"crossed msg1s; we are higher " | |
1029 | "priority => ignore incoming msg1"); | |
1030 | return True; | |
1031 | } else { | |
1032 | slog(st,LOG_DUMP,"crossed msg1s; we are lower " | |
1033 | "priority => use incoming msg1"); | |
1034 | if (process_msg1(st,buf,source)) { | |
1035 | BUF_FREE(&st->buffer); /* Free our old message 1 */ | |
ff05a229 | 1036 | enter_new_state(st,SITE_SENTMSG2); |
2fe58dfd SE |
1037 | } else { |
1038 | slog(st,LOG_ERROR,"failed to process an incoming " | |
1039 | "crossed msg1 (we have low priority)"); | |
1040 | } | |
1041 | BUF_FREE(buf); | |
1042 | return True; | |
1043 | } | |
1044 | } | |
1045 | /* The message 1 was received at an unexpected stage of the | |
1046 | key setup. XXX POLICY - what do we do? */ | |
1047 | slog(st,LOG_UNEXPECTED,"unexpected incoming message 1"); | |
1048 | BUF_FREE(buf); | |
1049 | return True; | |
1050 | } | |
1051 | return False; /* Not for us. */ | |
1052 | } | |
1053 | if (dest==(uint32_t)st) { | |
2fe58dfd | 1054 | /* Explicitly addressed to us */ |
ff05a229 | 1055 | uint32_t msgtype=ntohl(get_uint32(buf->start+8)); |
2fe58dfd SE |
1056 | if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True); |
1057 | switch (msgtype) { | |
794f2398 SE |
1058 | case 0: /* NAK */ |
1059 | /* If the source is our current peer then initiate a key setup, | |
1060 | because our peer's forgotten the key */ | |
1061 | if (get_uint32(buf->start+4)==st->remote_session_id) { | |
1062 | initiate_key_setup(st,"received a NAK"); | |
1063 | } else { | |
1064 | slog(st,LOG_SEC,"bad incoming NAK"); | |
1065 | } | |
1066 | break; | |
2fe58dfd SE |
1067 | case LABEL_MSG0: |
1068 | process_msg0(st,buf,source); | |
1069 | break; | |
1070 | case LABEL_MSG1: | |
1071 | /* Setup packet: should not have been explicitly addressed | |
1072 | to us */ | |
59635212 | 1073 | slog(st,LOG_SEC,"incoming explicitly addressed msg1"); |
2fe58dfd SE |
1074 | break; |
1075 | case LABEL_MSG2: | |
1076 | /* Setup packet: expected only in state SENTMSG1 */ | |
1077 | if (st->state!=SITE_SENTMSG1) { | |
1078 | slog(st,LOG_UNEXPECTED,"unexpected MSG2"); | |
1079 | } else if (process_msg2(st,buf,source)) | |
ff05a229 | 1080 | enter_new_state(st,SITE_SENTMSG3); |
2fe58dfd | 1081 | else { |
59635212 | 1082 | slog(st,LOG_SEC,"invalid MSG2"); |
2fe58dfd SE |
1083 | } |
1084 | break; | |
1085 | case LABEL_MSG3: | |
1086 | /* Setup packet: expected only in state SENTMSG2 */ | |
1087 | if (st->state!=SITE_SENTMSG2) { | |
1088 | slog(st,LOG_UNEXPECTED,"unexpected MSG3"); | |
1089 | } else if (process_msg3(st,buf,source)) | |
ff05a229 | 1090 | enter_new_state(st,SITE_SENTMSG4); |
2fe58dfd | 1091 | else { |
59635212 | 1092 | slog(st,LOG_SEC,"invalid MSG3"); |
2fe58dfd SE |
1093 | } |
1094 | break; | |
1095 | case LABEL_MSG4: | |
1096 | /* Setup packet: expected only in state SENTMSG3 */ | |
1097 | if (st->state!=SITE_SENTMSG3) { | |
1098 | slog(st,LOG_UNEXPECTED,"unexpected MSG4"); | |
1099 | } else if (process_msg4(st,buf,source)) | |
ff05a229 | 1100 | enter_new_state(st,SITE_SENTMSG5); |
2fe58dfd | 1101 | else { |
59635212 | 1102 | slog(st,LOG_SEC,"invalid MSG4"); |
2fe58dfd SE |
1103 | } |
1104 | break; | |
1105 | case LABEL_MSG5: | |
4efd681a SE |
1106 | /* Setup packet: expected only in state SENTMSG4 */ |
1107 | /* (may turn up in state RUN if our return MSG6 was lost | |
1108 | and the new key has already been activated. In that | |
1109 | case we should treat it as an ordinary PING packet. We | |
1110 | can't pass it to process_msg5() because the | |
ff05a229 | 1111 | new_transform will now be unkeyed. XXX) */ |
4efd681a | 1112 | if (st->state!=SITE_SENTMSG4) { |
2fe58dfd SE |
1113 | slog(st,LOG_UNEXPECTED,"unexpected MSG5"); |
1114 | } else if (process_msg5(st,buf,source)) { | |
ff05a229 | 1115 | enter_new_state(st,SITE_RUN); |
2fe58dfd | 1116 | } else { |
59635212 | 1117 | slog(st,LOG_SEC,"invalid MSG5"); |
2fe58dfd SE |
1118 | } |
1119 | break; | |
1120 | case LABEL_MSG6: | |
1121 | /* Setup packet: expected only in state SENTMSG5 */ | |
1122 | if (st->state!=SITE_SENTMSG5) { | |
1123 | slog(st,LOG_UNEXPECTED,"unexpected MSG6"); | |
1124 | } else if (process_msg6(st,buf,source)) { | |
1125 | BUF_FREE(&st->buffer); /* Free message 5 */ | |
1126 | activate_new_key(st); | |
1127 | } else { | |
59635212 | 1128 | slog(st,LOG_SEC,"invalid MSG6"); |
2fe58dfd SE |
1129 | } |
1130 | break; | |
2fe58dfd | 1131 | default: |
59635212 | 1132 | slog(st,LOG_SEC,"received message of unknown type 0x%08x", |
2fe58dfd SE |
1133 | msgtype); |
1134 | break; | |
1135 | } | |
1136 | BUF_FREE(buf); | |
1137 | return True; | |
1138 | } | |
1139 | ||
1140 | return False; | |
1141 | } | |
1142 | ||
1143 | static void site_control(void *vst, bool_t run) | |
1144 | { | |
1145 | struct site *st=vst; | |
1146 | if (run) enter_state_run(st); | |
1147 | else enter_state_stop(st); | |
1148 | } | |
1149 | ||
794f2398 SE |
1150 | static void site_phase_hook(void *sst, uint32_t newphase) |
1151 | { | |
1152 | struct site *st=sst; | |
1153 | ||
1154 | /* The program is shutting down; tell our peer */ | |
1155 | send_msg7(st,"shutting down"); | |
1156 | } | |
1157 | ||
2fe58dfd SE |
1158 | static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, |
1159 | list_t *args) | |
1160 | { | |
1161 | struct site *st; | |
1162 | item_t *item; | |
1163 | dict_t *dict; | |
1164 | ||
1165 | st=safe_malloc(sizeof(*st),"site_apply"); | |
1166 | ||
1167 | st->cl.description="site"; | |
1168 | st->cl.type=CL_SITE; | |
1169 | st->cl.apply=NULL; | |
1170 | st->cl.interface=&st->ops; | |
1171 | st->ops.st=st; | |
1172 | st->ops.control=site_control; | |
1173 | st->ops.status=site_status; | |
1174 | ||
1175 | /* First parameter must be a dict */ | |
1176 | item=list_elem(args,0); | |
1177 | if (!item || item->type!=t_dict) | |
1178 | cfgfatal(loc,"site","parameter must be a dictionary\n"); | |
1179 | ||
1180 | dict=item->data.dict; | |
558fa3fb SE |
1181 | st->localname=dict_read_string(dict, "local-name", True, "site", loc); |
1182 | st->remotename=dict_read_string(dict, "name", True, "site", loc); | |
1183 | /* Sanity check (which also allows the 'sites' file to include | |
1184 | site() closures for all sites including our own): refuse to | |
1185 | talk to ourselves */ | |
1186 | if (strcmp(st->localname,st->remotename)==0) { | |
b2a56f7c | 1187 | Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n", |
baa06aeb | 1188 | st->localname); |
558fa3fb SE |
1189 | free(st); |
1190 | return NULL; | |
1191 | } | |
469fd1d9 | 1192 | st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc); |
2fe58dfd SE |
1193 | st->comm=find_cl_if(dict,"comm",CL_COMM,True,"site",loc); |
1194 | st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc); | |
1195 | st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc); | |
1196 | st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc); | |
1197 | ||
2fe58dfd | 1198 | st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc); |
2fe58dfd | 1199 | st->address=dict_read_string(dict, "address", False, "site", loc); |
3454dce4 SE |
1200 | if (st->address) |
1201 | st->remoteport=dict_read_number(dict,"port",True,"site",loc,0); | |
1202 | else st->remoteport=0; | |
2fe58dfd SE |
1203 | st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc); |
1204 | ||
1205 | st->transform= | |
1206 | find_cl_if(dict,"transform",CL_TRANSFORM,True,"site",loc); | |
1207 | ||
1208 | st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc); | |
1209 | st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc); | |
1210 | ||
9d3a4132 SE |
1211 | st->key_lifetime=dict_read_number( |
1212 | dict,"key-lifetime",False,"site",loc,DEFAULT_KEY_LIFETIME); | |
1213 | if (st->key_lifetime < DEFAULT_KEY_RENEGOTIATE_GAP) | |
1214 | st->key_renegotiate_time=st->key_lifetime/2; | |
1215 | else | |
1216 | st->key_renegotiate_time=st->key_lifetime-DEFAULT_KEY_RENEGOTIATE_GAP; | |
1217 | st->setup_retries=dict_read_number( | |
1218 | dict,"setup-retries",False,"site",loc,DEFAULT_SETUP_RETRIES); | |
1219 | st->setup_timeout=dict_read_number( | |
1220 | dict,"setup-timeout",False,"site",loc,DEFAULT_SETUP_TIMEOUT); | |
1221 | st->wait_timeout=dict_read_number( | |
1222 | dict,"wait-time",False,"site",loc,DEFAULT_WAIT_TIME); | |
1223 | st->key_renegotiate_time=dict_read_number( | |
1224 | dict,"renegotiate-time",False,"site",loc,st->key_lifetime); | |
1225 | if (st->key_renegotiate_time > st->key_lifetime) { | |
1226 | cfgfatal(loc,"site", | |
1227 | "renegotiate-time must be less than key-lifetime\n"); | |
1228 | } | |
9d3a4132 SE |
1229 | st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False); |
1230 | ||
1231 | st->log_events=string_list_to_word(dict_lookup(dict,"log-events"), | |
1232 | log_event_table,"site"); | |
2fe58dfd | 1233 | |
4efd681a SE |
1234 | st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5, |
1235 | "site_apply"); | |
1236 | sprintf(st->tunname,"%s<->%s",st->localname,st->remotename); | |
1237 | ||
2fe58dfd SE |
1238 | /* The information we expect to see in incoming messages of type 1 */ |
1239 | st->setupsiglen=strlen(st->remotename)+strlen(st->localname)+8; | |
1240 | st->setupsig=safe_malloc(st->setupsiglen,"site_apply"); | |
8689b3a9 SE |
1241 | put_uint32(st->setupsig+0,LABEL_MSG1); |
1242 | put_uint16(st->setupsig+4,strlen(st->remotename)); | |
2fe58dfd | 1243 | memcpy(&st->setupsig[6],st->remotename,strlen(st->remotename)); |
8689b3a9 | 1244 | put_uint16(st->setupsig+(6+strlen(st->remotename)),strlen(st->localname)); |
2fe58dfd SE |
1245 | memcpy(&st->setupsig[8+strlen(st->remotename)],st->localname, |
1246 | strlen(st->localname)); | |
1247 | st->setup_priority=(strcmp(st->localname,st->remotename)>0); | |
1248 | ||
1249 | buffer_new(&st->buffer,SETUP_BUFFER_LEN); | |
1250 | ||
1251 | /* We are interested in poll(), but only for timeouts. We don't have | |
1252 | any fds of our own. */ | |
1253 | register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site"); | |
1254 | st->timeout=0; | |
1255 | ||
1256 | st->current_valid=False; | |
1257 | st->current_key_timeout=0; | |
1258 | st->peer_valid=False; | |
1259 | /* XXX mlock these */ | |
1260 | st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret"); | |
1261 | st->sharedsecret=safe_malloc(st->transform->keylen,"site:sharedsecret"); | |
1262 | ||
1263 | /* We need to register the remote networks with the netlink device */ | |
469fd1d9 | 1264 | st->netlink->reg(st->netlink->st, site_outgoing, st, |
ff05a229 SE |
1265 | st->transform->max_start_pad+(4*4)+ |
1266 | st->comm->min_start_pad, | |
1267 | st->transform->max_end_pad+st->comm->min_end_pad); | |
1268 | ||
2fe58dfd SE |
1269 | st->comm->request_notify(st->comm->st, st, site_incoming); |
1270 | ||
1271 | st->current_transform=st->transform->create(st->transform->st); | |
1272 | st->new_transform=st->transform->create(st->transform->st); | |
1273 | ||
1274 | enter_state_stop(st); | |
1275 | ||
794f2398 SE |
1276 | add_hook(PHASE_SHUTDOWN,site_phase_hook,st); |
1277 | ||
2fe58dfd SE |
1278 | return new_closure(&st->cl); |
1279 | } | |
1280 | ||
1281 | init_module site_module; | |
1282 | void site_module(dict_t *dict) | |
1283 | { | |
1284 | add_closure(dict,"site",site_apply); | |
1285 | } |