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> |
fe5e9cc4 | 19 | #include <limits.h> |
58650a70 | 20 | #include <assert.h> |
8689b3a9 | 21 | #include <sys/socket.h> |
2fe58dfd | 22 | |
8689b3a9 | 23 | #include <sys/mman.h> |
2fe58dfd | 24 | #include "util.h" |
59635212 | 25 | #include "unaligned.h" |
ff05a229 | 26 | #include "magic.h" |
2fe58dfd SE |
27 | |
28 | #define SETUP_BUFFER_LEN 2048 | |
29 | ||
9d3a4132 SE |
30 | #define DEFAULT_KEY_LIFETIME 3600000 /* One hour */ |
31 | #define DEFAULT_KEY_RENEGOTIATE_GAP 300000 /* Five minutes */ | |
2fe58dfd | 32 | #define DEFAULT_SETUP_RETRIES 5 |
4f5e39ec | 33 | #define DEFAULT_SETUP_TIMEOUT 2000 |
3454dce4 | 34 | #define DEFAULT_WAIT_TIME 20000 |
2fe58dfd SE |
35 | |
36 | /* Each site can be in one of several possible states. */ | |
37 | ||
38 | /* States: | |
39 | SITE_STOP - nothing is allowed to happen; tunnel is down; | |
40 | all session keys have been erased | |
41 | -> SITE_RUN upon external instruction | |
42 | SITE_RUN - site up, maybe with valid key | |
43 | -> SITE_RESOLVE upon outgoing packet and no valid key | |
44 | we start name resolution for the other end of the tunnel | |
45 | -> SITE_SENTMSG2 upon valid incoming message 1 and suitable time | |
46 | we send an appropriate message 2 | |
47 | SITE_RESOLVE - waiting for name resolution | |
48 | -> SITE_SENTMSG1 upon successful resolution | |
49 | we send an appropriate message 1 | |
50 | -> SITE_SENTMSG2 upon valid incoming message 1 (then abort resolution) | |
51 | we abort resolution and | |
52 | -> SITE_WAIT on timeout or resolution failure | |
53 | SITE_SENTMSG1 | |
54 | -> SITE_SENTMSG2 upon valid incoming message 1 from higher priority end | |
55 | -> SITE_SENTMSG3 upon valid incoming message 2 | |
56 | -> SITE_WAIT on timeout | |
57 | SITE_SENTMSG2 | |
58 | -> SITE_SENTMSG4 upon valid incoming message 3 | |
59 | -> SITE_WAIT on timeout | |
60 | SITE_SENTMSG3 | |
61 | -> SITE_SENTMSG5 upon valid incoming message 4 | |
62 | -> SITE_WAIT on timeout | |
63 | SITE_SENTMSG4 | |
64 | -> SITE_RUN upon valid incoming message 5 | |
65 | -> SITE_WAIT on timeout | |
66 | SITE_SENTMSG5 | |
67 | -> SITE_RUN upon valid incoming message 6 | |
68 | -> SITE_WAIT on timeout | |
69 | SITE_WAIT - failed to establish key; do nothing for a while | |
70 | -> SITE_RUN on timeout | |
71 | */ | |
72 | ||
73 | #define SITE_STOP 0 | |
74 | #define SITE_RUN 1 | |
75 | #define SITE_RESOLVE 2 | |
76 | #define SITE_SENTMSG1 3 | |
77 | #define SITE_SENTMSG2 4 | |
78 | #define SITE_SENTMSG3 5 | |
79 | #define SITE_SENTMSG4 6 | |
80 | #define SITE_SENTMSG5 7 | |
81 | #define SITE_WAIT 8 | |
82 | ||
fe5e9cc4 | 83 | static cstring_t state_name(uint32_t state) |
2fe58dfd SE |
84 | { |
85 | switch (state) { | |
3454dce4 SE |
86 | case 0: return "STOP"; |
87 | case 1: return "RUN"; | |
88 | case 2: return "RESOLVE"; | |
89 | case 3: return "SENTMSG1"; | |
90 | case 4: return "SENTMSG2"; | |
91 | case 5: return "SENTMSG3"; | |
92 | case 6: return "SENTMSG4"; | |
93 | case 7: return "SENTMSG5"; | |
94 | case 8: return "WAIT"; | |
2fe58dfd SE |
95 | default: return "*bad state*"; |
96 | } | |
97 | } | |
98 | ||
2fe58dfd SE |
99 | #define NONCELEN 8 |
100 | ||
101 | #define LOG_UNEXPECTED 0x00000001 | |
102 | #define LOG_SETUP_INIT 0x00000002 | |
103 | #define LOG_SETUP_TIMEOUT 0x00000004 | |
104 | #define LOG_ACTIVATE_KEY 0x00000008 | |
105 | #define LOG_TIMEOUT_KEY 0x00000010 | |
9d3a4132 | 106 | #define LOG_SEC 0x00000020 |
2fe58dfd SE |
107 | #define LOG_STATE 0x00000040 |
108 | #define LOG_DROP 0x00000080 | |
109 | #define LOG_DUMP 0x00000100 | |
110 | #define LOG_ERROR 0x00000400 | |
111 | ||
9d3a4132 SE |
112 | static struct flagstr log_event_table[]={ |
113 | { "unexpected", LOG_UNEXPECTED }, | |
114 | { "setup-init", LOG_SETUP_INIT }, | |
115 | { "setup-timeout", LOG_SETUP_TIMEOUT }, | |
116 | { "activate-key", LOG_ACTIVATE_KEY }, | |
117 | { "timeout-key", LOG_TIMEOUT_KEY }, | |
118 | { "security", LOG_SEC }, | |
119 | { "state-change", LOG_STATE }, | |
120 | { "packet-drop", LOG_DROP }, | |
121 | { "dump-packets", LOG_DUMP }, | |
122 | { "errors", LOG_ERROR }, | |
ff05a229 SE |
123 | { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT| |
124 | LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR }, | |
9d3a4132 SE |
125 | { "all", 0xffffffff }, |
126 | { NULL, 0 } | |
127 | }; | |
128 | ||
2fe58dfd SE |
129 | struct site { |
130 | closure_t cl; | |
131 | struct site_if ops; | |
132 | /* configuration information */ | |
133 | string_t localname; | |
134 | string_t remotename; | |
ff05a229 | 135 | string_t tunname; /* localname<->remotename by default, used in logs */ |
2fe58dfd | 136 | string_t address; /* DNS name for bootstrapping, optional */ |
ff05a229 | 137 | int remoteport; /* Port for bootstrapping, optional */ |
2fe58dfd SE |
138 | struct netlink_if *netlink; |
139 | struct comm_if *comm; | |
140 | struct resolver_if *resolver; | |
141 | struct log_if *log; | |
142 | struct random_if *random; | |
143 | struct rsaprivkey_if *privkey; | |
2fe58dfd SE |
144 | struct rsapubkey_if *pubkey; |
145 | struct transform_if *transform; | |
146 | struct dh_if *dh; | |
147 | struct hash_if *hash; | |
2fe58dfd | 148 | |
58650a70 | 149 | uint32_t index; /* Index of this site */ |
1caa23ff | 150 | int32_t setup_retries; /* How many times to send setup packets */ |
4a8aed08 IJ |
151 | int32_t setup_timeout; /* Initial timeout for setup packets */ |
152 | int32_t wait_timeout; /* How long to wait if setup unsuccessful */ | |
153 | int32_t key_lifetime; /* How long a key lasts once set up */ | |
154 | int32_t key_renegotiate_time; /* If we see traffic (or a keepalive) | |
9d3a4132 SE |
155 | after this time, initiate a new |
156 | key exchange */ | |
ff05a229 SE |
157 | bool_t keepalive; /* Send keepalives to detect peer failure (not yet |
158 | implemented) */ | |
2fe58dfd SE |
159 | |
160 | uint8_t *setupsig; /* Expected signature of incoming MSG1 packets */ | |
1caa23ff IJ |
161 | int32_t setupsiglen; /* Allows us to discard packets quickly if |
162 | they are not for us */ | |
2fe58dfd SE |
163 | bool_t setup_priority; /* Do we have precedence if both sites emit |
164 | message 1 simultaneously? */ | |
165 | uint32_t log_events; | |
166 | ||
167 | /* runtime information */ | |
168 | uint32_t state; | |
169 | uint64_t now; /* Most recently seen time */ | |
170 | ||
ff05a229 | 171 | /* The currently established session */ |
2fe58dfd SE |
172 | uint32_t remote_session_id; |
173 | struct transform_inst_if *current_transform; | |
174 | bool_t current_valid; | |
175 | uint64_t current_key_timeout; /* End of life of current key */ | |
ff05a229 | 176 | uint64_t renegotiate_key_time; /* When we can negotiate a new key */ |
2fe58dfd SE |
177 | struct sockaddr_in peer; /* Current address of peer */ |
178 | bool_t peer_valid; /* Peer address becomes invalid when key times out, | |
179 | but only if we have a DNS name for our peer */ | |
180 | ||
ff05a229 SE |
181 | /* The current key setup protocol exchange. We can only be |
182 | involved in one of these at a time. There's a potential for | |
183 | denial of service here (the attacker keeps sending a setup | |
184 | packet; we keep trying to continue the exchange, and have to | |
185 | timeout before we can listen for another setup packet); perhaps | |
186 | we should keep a list of 'bad' sources for setup packets. */ | |
2fe58dfd SE |
187 | uint32_t setup_session_id; |
188 | struct sockaddr_in setup_peer; | |
189 | uint8_t localN[NONCELEN]; /* Nonces for key exchange */ | |
190 | uint8_t remoteN[NONCELEN]; | |
191 | struct buffer_if buffer; /* Current outgoing key exchange packet */ | |
4a8aed08 | 192 | int32_t retries; /* Number of retries remaining */ |
2fe58dfd SE |
193 | uint64_t timeout; /* Timeout for current state */ |
194 | uint8_t *dhsecret; | |
195 | uint8_t *sharedsecret; | |
2fe58dfd SE |
196 | struct transform_inst_if *new_transform; /* For key setup/verify */ |
197 | }; | |
198 | ||
fe5e9cc4 | 199 | static void slog(struct site *st, uint32_t event, cstring_t msg, ...) |
2fe58dfd SE |
200 | { |
201 | va_list ap; | |
7c006408 | 202 | char buf[240]; |
b2a56f7c | 203 | uint32_t class; |
2fe58dfd SE |
204 | |
205 | va_start(ap,msg); | |
206 | ||
207 | if (event&st->log_events) { | |
b2a56f7c SE |
208 | switch(event) { |
209 | case LOG_UNEXPECTED: class=M_INFO; break; | |
210 | case LOG_SETUP_INIT: class=M_INFO; break; | |
211 | case LOG_SETUP_TIMEOUT: class=M_NOTICE; break; | |
212 | case LOG_ACTIVATE_KEY: class=M_INFO; break; | |
213 | case LOG_TIMEOUT_KEY: class=M_INFO; break; | |
214 | case LOG_SEC: class=M_SECURITY; break; | |
215 | case LOG_STATE: class=M_DEBUG; break; | |
216 | case LOG_DROP: class=M_DEBUG; break; | |
217 | case LOG_DUMP: class=M_DEBUG; break; | |
469fd1d9 SE |
218 | case LOG_ERROR: class=M_ERR; break; |
219 | default: class=M_ERR; break; | |
b2a56f7c SE |
220 | } |
221 | ||
c1d2109a | 222 | vsnprintf(buf,sizeof(buf),msg,ap); |
b2a56f7c | 223 | st->log->log(st->log->st,class,"%s: %s",st->tunname,buf); |
2fe58dfd SE |
224 | } |
225 | va_end(ap); | |
226 | } | |
227 | ||
9d3a4132 | 228 | static void set_link_quality(struct site *st); |
fe5e9cc4 SE |
229 | static void delete_key(struct site *st, cstring_t reason, uint32_t loglevel); |
230 | static bool_t initiate_key_setup(struct site *st, cstring_t reason); | |
2fe58dfd SE |
231 | static void enter_state_run(struct site *st); |
232 | static bool_t enter_state_resolve(struct site *st); | |
ff05a229 | 233 | static bool_t enter_new_state(struct site *st,uint32_t next); |
2fe58dfd SE |
234 | static void enter_state_wait(struct site *st); |
235 | ||
236 | #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0) | |
237 | #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0) | |
238 | #define CHECK_TYPE(b,t) do { uint32_t type; \ | |
239 | CHECK_AVAIL((b),4); \ | |
59635212 | 240 | type=buf_unprepend_uint32((b)); \ |
2fe58dfd SE |
241 | if (type!=(t)) return False; } while(0) |
242 | ||
243 | struct msg { | |
244 | uint8_t *hashstart; | |
245 | uint32_t dest; | |
246 | uint32_t source; | |
1caa23ff | 247 | int32_t remlen; |
2fe58dfd | 248 | uint8_t *remote; |
1caa23ff | 249 | int32_t loclen; |
2fe58dfd SE |
250 | uint8_t *local; |
251 | uint8_t *nR; | |
252 | uint8_t *nL; | |
1caa23ff | 253 | int32_t pklen; |
3e8addad | 254 | char *pk; |
1caa23ff IJ |
255 | int32_t hashlen; |
256 | int32_t siglen; | |
3e8addad | 257 | char *sig; |
2fe58dfd SE |
258 | }; |
259 | ||
ff05a229 SE |
260 | /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside |
261 | out using a transform of config data supplied by netlink */ | |
fe5e9cc4 | 262 | static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what) |
2fe58dfd SE |
263 | { |
264 | void *hst; | |
3b83c932 | 265 | uint8_t *hash; |
2fe58dfd SE |
266 | string_t dhpub, sig; |
267 | ||
268 | st->retries=st->setup_retries; | |
269 | BUF_ALLOC(&st->buffer,what); | |
270 | buffer_init(&st->buffer,0); | |
59635212 SE |
271 | buf_append_uint32(&st->buffer, |
272 | (type==LABEL_MSG1?0:st->setup_session_id)); | |
58650a70 | 273 | buf_append_uint32(&st->buffer,st->index); |
59635212 | 274 | buf_append_uint32(&st->buffer,type); |
2fe58dfd SE |
275 | buf_append_string(&st->buffer,st->localname); |
276 | buf_append_string(&st->buffer,st->remotename); | |
277 | memcpy(buf_append(&st->buffer,NONCELEN),st->localN,NONCELEN); | |
278 | if (type==LABEL_MSG1) return True; | |
279 | memcpy(buf_append(&st->buffer,NONCELEN),st->remoteN,NONCELEN); | |
280 | if (type==LABEL_MSG2) return True; | |
3b83c932 SE |
281 | |
282 | if (hacky_par_mid_failnow()) return False; | |
283 | ||
2fe58dfd SE |
284 | dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len); |
285 | buf_append_string(&st->buffer,dhpub); | |
286 | free(dhpub); | |
3b83c932 | 287 | hash=safe_malloc(st->hash->len, "generate_msg"); |
2fe58dfd SE |
288 | hst=st->hash->init(); |
289 | st->hash->update(hst,st->buffer.start,st->buffer.size); | |
290 | st->hash->final(hst,hash); | |
291 | sig=st->privkey->sign(st->privkey->st,hash,st->hash->len); | |
292 | buf_append_string(&st->buffer,sig); | |
293 | free(sig); | |
3b83c932 | 294 | free(hash); |
2fe58dfd SE |
295 | return True; |
296 | } | |
297 | ||
298 | static bool_t unpick_msg(struct site *st, uint32_t type, | |
299 | struct buffer_if *msg, struct msg *m) | |
300 | { | |
301 | m->hashstart=msg->start; | |
302 | CHECK_AVAIL(msg,4); | |
59635212 | 303 | m->dest=buf_unprepend_uint32(msg); |
2fe58dfd | 304 | CHECK_AVAIL(msg,4); |
59635212 | 305 | m->source=buf_unprepend_uint32(msg); |
2fe58dfd SE |
306 | CHECK_TYPE(msg,type); |
307 | CHECK_AVAIL(msg,2); | |
59635212 | 308 | m->remlen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
309 | CHECK_AVAIL(msg,m->remlen); |
310 | m->remote=buf_unprepend(msg,m->remlen); | |
311 | CHECK_AVAIL(msg,2); | |
59635212 | 312 | m->loclen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
313 | CHECK_AVAIL(msg,m->loclen); |
314 | m->local=buf_unprepend(msg,m->loclen); | |
315 | CHECK_AVAIL(msg,NONCELEN); | |
316 | m->nR=buf_unprepend(msg,NONCELEN); | |
317 | if (type==LABEL_MSG1) { | |
318 | CHECK_EMPTY(msg); | |
319 | return True; | |
320 | } | |
321 | CHECK_AVAIL(msg,NONCELEN); | |
322 | m->nL=buf_unprepend(msg,NONCELEN); | |
323 | if (type==LABEL_MSG2) { | |
324 | CHECK_EMPTY(msg); | |
325 | return True; | |
326 | } | |
327 | CHECK_AVAIL(msg,2); | |
59635212 | 328 | m->pklen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
329 | CHECK_AVAIL(msg,m->pklen); |
330 | m->pk=buf_unprepend(msg,m->pklen); | |
331 | m->hashlen=msg->start-m->hashstart; | |
332 | CHECK_AVAIL(msg,2); | |
59635212 | 333 | m->siglen=buf_unprepend_uint16(msg); |
2fe58dfd SE |
334 | CHECK_AVAIL(msg,m->siglen); |
335 | m->sig=buf_unprepend(msg,m->siglen); | |
336 | CHECK_EMPTY(msg); | |
337 | return True; | |
338 | } | |
339 | ||
ff05a229 | 340 | static bool_t check_msg(struct site *st, uint32_t type, struct msg *m, |
fe5e9cc4 | 341 | cstring_t *error) |
ff05a229 SE |
342 | { |
343 | if (type==LABEL_MSG1) return True; | |
344 | ||
345 | /* Check that the site names and our nonce have been sent | |
346 | back correctly, and then store our peer's nonce. */ | |
347 | if (memcmp(m->remote,st->remotename,strlen(st->remotename)!=0)) { | |
348 | *error="wrong remote site name"; | |
349 | return False; | |
350 | } | |
351 | if (memcmp(m->local,st->localname,strlen(st->localname)!=0)) { | |
352 | *error="wrong local site name"; | |
353 | return False; | |
354 | } | |
355 | if (memcmp(m->nL,st->localN,NONCELEN)!=0) { | |
356 | *error="wrong locally-generated nonce"; | |
357 | return False; | |
358 | } | |
359 | if (type==LABEL_MSG2) return True; | |
360 | if (memcmp(m->nR,st->remoteN,NONCELEN)!=0) { | |
361 | *error="wrong remotely-generated nonce"; | |
362 | return False; | |
363 | } | |
364 | if (type==LABEL_MSG3) return True; | |
365 | if (type==LABEL_MSG4) return True; | |
366 | *error="unknown message type"; | |
367 | return False; | |
368 | } | |
369 | ||
2fe58dfd SE |
370 | static bool_t generate_msg1(struct site *st) |
371 | { | |
372 | st->random->generate(st->random->st,NONCELEN,st->localN); | |
373 | return generate_msg(st,LABEL_MSG1,"site:MSG1"); | |
374 | } | |
375 | ||
376 | static bool_t process_msg1(struct site *st, struct buffer_if *msg1, | |
377 | struct sockaddr_in *src) | |
378 | { | |
379 | struct msg m; | |
380 | ||
381 | /* We've already determined we're in an appropriate state to | |
382 | process an incoming MSG1, and that the MSG1 has correct values | |
383 | of A and B. */ | |
384 | ||
385 | if (!unpick_msg(st,LABEL_MSG1,msg1,&m)) return False; | |
386 | ||
2fe58dfd | 387 | st->setup_peer=*src; |
2fe58dfd SE |
388 | st->setup_session_id=m.source; |
389 | memcpy(st->remoteN,m.nR,NONCELEN); | |
390 | return True; | |
391 | } | |
392 | ||
393 | static bool_t generate_msg2(struct site *st) | |
394 | { | |
395 | st->random->generate(st->random->st,NONCELEN,st->localN); | |
396 | return generate_msg(st,LABEL_MSG2,"site:MSG2"); | |
397 | } | |
398 | ||
399 | static bool_t process_msg2(struct site *st, struct buffer_if *msg2, | |
400 | struct sockaddr_in *src) | |
401 | { | |
402 | struct msg m; | |
fe5e9cc4 | 403 | cstring_t err; |
2fe58dfd SE |
404 | |
405 | if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False; | |
ff05a229 SE |
406 | if (!check_msg(st,LABEL_MSG2,&m,&err)) { |
407 | slog(st,LOG_SEC,"msg2: %s",err); | |
2fe58dfd SE |
408 | return False; |
409 | } | |
410 | st->setup_session_id=m.source; | |
411 | memcpy(st->remoteN,m.nR,NONCELEN); | |
412 | return True; | |
413 | } | |
414 | ||
415 | static bool_t generate_msg3(struct site *st) | |
416 | { | |
417 | /* Now we have our nonce and their nonce. Think of a secret key, | |
418 | and create message number 3. */ | |
419 | st->random->generate(st->random->st,st->dh->len,st->dhsecret); | |
420 | return generate_msg(st,LABEL_MSG3,"site:MSG3"); | |
421 | } | |
422 | ||
423 | static bool_t process_msg3(struct site *st, struct buffer_if *msg3, | |
424 | struct sockaddr_in *src) | |
425 | { | |
426 | struct msg m; | |
3b83c932 | 427 | uint8_t *hash; |
2fe58dfd | 428 | void *hst; |
fe5e9cc4 | 429 | cstring_t err; |
2fe58dfd SE |
430 | |
431 | if (!unpick_msg(st,LABEL_MSG3,msg3,&m)) return False; | |
ff05a229 SE |
432 | if (!check_msg(st,LABEL_MSG3,&m,&err)) { |
433 | slog(st,LOG_SEC,"msg3: %s",err); | |
2fe58dfd SE |
434 | return False; |
435 | } | |
ff05a229 | 436 | |
2fe58dfd | 437 | /* Check signature and store g^x mod m */ |
3b83c932 | 438 | hash=safe_malloc(st->hash->len, "process_msg3"); |
2fe58dfd SE |
439 | hst=st->hash->init(); |
440 | st->hash->update(hst,m.hashstart,m.hashlen); | |
441 | st->hash->final(hst,hash); | |
442 | /* Terminate signature with a '0' - cheating, but should be ok */ | |
443 | m.sig[m.siglen]=0; | |
444 | if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) { | |
59635212 | 445 | slog(st,LOG_SEC,"msg3 signature failed check!"); |
3b83c932 | 446 | free(hash); |
2fe58dfd SE |
447 | return False; |
448 | } | |
3b83c932 | 449 | free(hash); |
2fe58dfd SE |
450 | |
451 | /* Terminate their DH public key with a '0' */ | |
452 | m.pk[m.pklen]=0; | |
453 | /* Invent our DH secret key */ | |
454 | st->random->generate(st->random->st,st->dh->len,st->dhsecret); | |
455 | ||
456 | /* Generate the shared key */ | |
457 | st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,m.pk, | |
458 | st->sharedsecret,st->transform->keylen); | |
459 | ||
460 | /* Set up the transform */ | |
461 | st->new_transform->setkey(st->new_transform->st,st->sharedsecret, | |
462 | st->transform->keylen); | |
463 | ||
464 | return True; | |
465 | } | |
466 | ||
467 | static bool_t generate_msg4(struct site *st) | |
468 | { | |
469 | /* We have both nonces, their public key and our private key. Generate | |
470 | our public key, sign it and send it to them. */ | |
471 | return generate_msg(st,LABEL_MSG4,"site:MSG4"); | |
472 | } | |
473 | ||
474 | static bool_t process_msg4(struct site *st, struct buffer_if *msg4, | |
475 | struct sockaddr_in *src) | |
476 | { | |
477 | struct msg m; | |
3b83c932 | 478 | uint8_t *hash; |
2fe58dfd | 479 | void *hst; |
fe5e9cc4 | 480 | cstring_t err; |
2fe58dfd SE |
481 | |
482 | if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False; | |
ff05a229 SE |
483 | if (!check_msg(st,LABEL_MSG4,&m,&err)) { |
484 | slog(st,LOG_SEC,"msg4: %s",err); | |
2fe58dfd SE |
485 | return False; |
486 | } | |
487 | ||
488 | /* Check signature and store g^x mod m */ | |
3b83c932 | 489 | hash=safe_malloc(st->hash->len, "process_msg4"); |
2fe58dfd SE |
490 | hst=st->hash->init(); |
491 | st->hash->update(hst,m.hashstart,m.hashlen); | |
492 | st->hash->final(hst,hash); | |
493 | /* Terminate signature with a '0' - cheating, but should be ok */ | |
494 | m.sig[m.siglen]=0; | |
495 | if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m.sig)) { | |
59635212 | 496 | slog(st,LOG_SEC,"msg4 signature failed check!"); |
3b83c932 | 497 | free(hash); |
2fe58dfd SE |
498 | return False; |
499 | } | |
3b83c932 | 500 | free(hash); |
2fe58dfd SE |
501 | |
502 | /* Terminate their DH public key with a '0' */ | |
503 | m.pk[m.pklen]=0; | |
504 | /* Generate the shared key */ | |
505 | st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,m.pk, | |
506 | st->sharedsecret,st->transform->keylen); | |
507 | /* Set up the transform */ | |
508 | st->new_transform->setkey(st->new_transform->st,st->sharedsecret, | |
509 | st->transform->keylen); | |
510 | ||
511 | return True; | |
512 | } | |
513 | ||
2fe58dfd SE |
514 | struct msg0 { |
515 | uint32_t dest; | |
516 | uint32_t source; | |
517 | uint32_t type; | |
518 | }; | |
519 | ||
520 | static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0, | |
521 | struct msg0 *m) | |
522 | { | |
523 | CHECK_AVAIL(msg0,4); | |
59635212 | 524 | m->dest=buf_unprepend_uint32(msg0); |
2fe58dfd | 525 | CHECK_AVAIL(msg0,4); |
59635212 | 526 | m->source=buf_unprepend_uint32(msg0); |
2fe58dfd | 527 | CHECK_AVAIL(msg0,4); |
59635212 | 528 | m->type=buf_unprepend_uint32(msg0); |
2fe58dfd SE |
529 | return True; |
530 | /* Leaves transformed part of buffer untouched */ | |
531 | } | |
532 | ||
ff05a229 SE |
533 | static bool_t generate_msg5(struct site *st) |
534 | { | |
fe5e9cc4 | 535 | cstring_t transform_err; |
ff05a229 SE |
536 | |
537 | BUF_ALLOC(&st->buffer,"site:MSG5"); | |
538 | /* We are going to add four words to the message */ | |
539 | buffer_init(&st->buffer,st->transform->max_start_pad+(4*4)); | |
540 | /* Give the netlink code an opportunity to put its own stuff in the | |
541 | message (configuration information, etc.) */ | |
542 | st->netlink->output_config(st->netlink->st,&st->buffer); | |
543 | buf_prepend_uint32(&st->buffer,LABEL_MSG5); | |
544 | st->new_transform->forwards(st->new_transform->st,&st->buffer, | |
545 | &transform_err); | |
546 | buf_prepend_uint32(&st->buffer,LABEL_MSG5); | |
58650a70 | 547 | buf_prepend_uint32(&st->buffer,st->index); |
ff05a229 SE |
548 | buf_prepend_uint32(&st->buffer,st->setup_session_id); |
549 | ||
550 | st->retries=st->setup_retries; | |
551 | return True; | |
552 | } | |
553 | ||
2fe58dfd SE |
554 | static bool_t process_msg5(struct site *st, struct buffer_if *msg5, |
555 | struct sockaddr_in *src) | |
556 | { | |
557 | struct msg0 m; | |
fe5e9cc4 | 558 | cstring_t transform_err; |
2fe58dfd SE |
559 | |
560 | if (!unpick_msg0(st,msg5,&m)) return False; | |
561 | ||
562 | if (st->new_transform->reverse(st->new_transform->st, | |
563 | msg5,&transform_err)) { | |
564 | /* There's a problem */ | |
59635212 | 565 | slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err); |
2fe58dfd SE |
566 | return False; |
567 | } | |
568 | /* Buffer should now contain untransformed PING packet data */ | |
569 | CHECK_AVAIL(msg5,4); | |
59635212 | 570 | if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) { |
ff05a229 | 571 | slog(st,LOG_SEC,"MSG5/PING packet contained wrong label"); |
2fe58dfd SE |
572 | return False; |
573 | } | |
794f2398 SE |
574 | if (!st->netlink->check_config(st->netlink->st,msg5)) { |
575 | slog(st,LOG_SEC,"MSG5/PING packet contained bad netlink config"); | |
576 | return False; | |
577 | } | |
2fe58dfd SE |
578 | CHECK_EMPTY(msg5); |
579 | return True; | |
580 | } | |
581 | ||
582 | static bool_t generate_msg6(struct site *st) | |
583 | { | |
fe5e9cc4 | 584 | cstring_t transform_err; |
2fe58dfd SE |
585 | |
586 | BUF_ALLOC(&st->buffer,"site:MSG6"); | |
ff05a229 SE |
587 | /* We are going to add four words to the message */ |
588 | buffer_init(&st->buffer,st->transform->max_start_pad+(4*4)); | |
794f2398 SE |
589 | /* Give the netlink code an opportunity to put its own stuff in the |
590 | message (configuration information, etc.) */ | |
591 | st->netlink->output_config(st->netlink->st,&st->buffer); | |
ff05a229 | 592 | buf_prepend_uint32(&st->buffer,LABEL_MSG6); |
2fe58dfd SE |
593 | st->new_transform->forwards(st->new_transform->st,&st->buffer, |
594 | &transform_err); | |
59635212 | 595 | buf_prepend_uint32(&st->buffer,LABEL_MSG6); |
58650a70 | 596 | buf_prepend_uint32(&st->buffer,st->index); |
59635212 | 597 | buf_prepend_uint32(&st->buffer,st->setup_session_id); |
2fe58dfd | 598 | |
ff05a229 | 599 | st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */ |
2fe58dfd SE |
600 | return True; |
601 | } | |
602 | ||
603 | static bool_t process_msg6(struct site *st, struct buffer_if *msg6, | |
604 | struct sockaddr_in *src) | |
605 | { | |
606 | struct msg0 m; | |
fe5e9cc4 | 607 | cstring_t transform_err; |
2fe58dfd SE |
608 | |
609 | if (!unpick_msg0(st,msg6,&m)) return False; | |
610 | ||
611 | if (st->new_transform->reverse(st->new_transform->st, | |
612 | msg6,&transform_err)) { | |
613 | /* There's a problem */ | |
59635212 | 614 | slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err); |
2fe58dfd SE |
615 | return False; |
616 | } | |
617 | /* Buffer should now contain untransformed PING packet data */ | |
618 | CHECK_AVAIL(msg6,4); | |
59635212 SE |
619 | if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) { |
620 | slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data"); | |
2fe58dfd SE |
621 | return False; |
622 | } | |
794f2398 SE |
623 | if (!st->netlink->check_config(st->netlink->st,msg6)) { |
624 | slog(st,LOG_SEC,"MSG6/PONG packet contained bad netlink config"); | |
625 | return False; | |
626 | } | |
2fe58dfd SE |
627 | CHECK_EMPTY(msg6); |
628 | return True; | |
629 | } | |
630 | ||
631 | static bool_t process_msg0(struct site *st, struct buffer_if *msg0, | |
632 | struct sockaddr_in *src) | |
633 | { | |
634 | struct msg0 m; | |
fe5e9cc4 | 635 | cstring_t transform_err; |
2fe58dfd SE |
636 | uint32_t type; |
637 | ||
638 | if (!st->current_valid) { | |
639 | slog(st,LOG_DROP,"incoming message but no current key -> dropping"); | |
794f2398 | 640 | return initiate_key_setup(st,"incoming message but no current key"); |
2fe58dfd SE |
641 | } |
642 | ||
643 | if (!unpick_msg0(st,msg0,&m)) return False; | |
644 | ||
645 | if (st->current_transform->reverse(st->current_transform->st, | |
646 | msg0,&transform_err)) { | |
647 | /* There's a problem */ | |
59635212 | 648 | slog(st,LOG_SEC,"transform: %s",transform_err); |
794f2398 | 649 | return initiate_key_setup(st,"incoming message would not decrypt"); |
2fe58dfd SE |
650 | } |
651 | CHECK_AVAIL(msg0,4); | |
59635212 | 652 | type=buf_unprepend_uint32(msg0); |
2fe58dfd | 653 | switch(type) { |
794f2398 SE |
654 | case LABEL_MSG7: |
655 | /* We must forget about the current session. */ | |
656 | delete_key(st,"request from peer",LOG_SEC); | |
657 | return True; | |
658 | break; | |
2fe58dfd SE |
659 | case LABEL_MSG9: |
660 | /* Deliver to netlink layer */ | |
469fd1d9 | 661 | st->netlink->deliver(st->netlink->st,msg0); |
2fe58dfd SE |
662 | return True; |
663 | break; | |
664 | default: | |
ff05a229 SE |
665 | slog(st,LOG_SEC,"incoming encrypted message of type %08x " |
666 | "(unknown)",type); | |
2fe58dfd SE |
667 | break; |
668 | } | |
669 | return False; | |
670 | } | |
671 | ||
672 | static void dump_packet(struct site *st, struct buffer_if *buf, | |
673 | struct sockaddr_in *addr, bool_t incoming) | |
674 | { | |
59635212 SE |
675 | uint32_t dest=ntohl(*(uint32_t *)buf->start); |
676 | uint32_t source=ntohl(*(uint32_t *)(buf->start+4)); | |
677 | uint32_t msgtype=ntohl(*(uint32_t *)(buf->start+8)); | |
2fe58dfd SE |
678 | |
679 | if (st->log_events & LOG_DUMP) | |
040ee979 SE |
680 | slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:", |
681 | st->tunname,incoming?"incoming":"outgoing", | |
682 | dest,source,msgtype); | |
2fe58dfd SE |
683 | } |
684 | ||
685 | static uint32_t site_status(void *st) | |
686 | { | |
687 | return 0; | |
688 | } | |
689 | ||
690 | static bool_t send_msg(struct site *st) | |
691 | { | |
692 | if (st->retries>0) { | |
693 | dump_packet(st,&st->buffer,&st->setup_peer,False); | |
694 | st->comm->sendmsg(st->comm->st,&st->buffer,&st->setup_peer); | |
695 | st->timeout=st->now+st->setup_timeout; | |
696 | st->retries--; | |
697 | return True; | |
698 | } else { | |
3454dce4 SE |
699 | slog(st,LOG_SETUP_TIMEOUT,"timed out sending key setup packet " |
700 | "(in state %s)",state_name(st->state)); | |
2fe58dfd SE |
701 | enter_state_wait(st); |
702 | return False; | |
703 | } | |
704 | } | |
705 | ||
706 | static void site_resolve_callback(void *sst, struct in_addr *address) | |
707 | { | |
708 | struct site *st=sst; | |
709 | ||
710 | if (st->state!=SITE_RESOLVE) { | |
711 | slog(st,LOG_UNEXPECTED,"site_resolve_callback called unexpectedly"); | |
712 | return; | |
713 | } | |
714 | if (address) { | |
715 | memset(&st->setup_peer,0,sizeof(st->setup_peer)); | |
716 | st->setup_peer.sin_family=AF_INET; | |
717 | st->setup_peer.sin_port=htons(st->remoteport); | |
718 | st->setup_peer.sin_addr=*address; | |
ff05a229 | 719 | enter_new_state(st,SITE_SENTMSG1); |
2fe58dfd SE |
720 | } else { |
721 | /* Resolution failed */ | |
722 | slog(st,LOG_ERROR,"resolution of %s failed",st->address); | |
723 | enter_state_run(st); | |
724 | } | |
725 | } | |
726 | ||
fe5e9cc4 | 727 | static bool_t initiate_key_setup(struct site *st, cstring_t reason) |
9d3a4132 SE |
728 | { |
729 | if (st->state!=SITE_RUN) return False; | |
794f2398 | 730 | slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason); |
9d3a4132 | 731 | if (st->address) { |
794f2398 | 732 | slog(st,LOG_SETUP_INIT,"resolving peer address"); |
9d3a4132 SE |
733 | return enter_state_resolve(st); |
734 | } else if (st->peer_valid) { | |
794f2398 | 735 | slog(st,LOG_SETUP_INIT,"using old peer address"); |
9d3a4132 | 736 | st->setup_peer=st->peer; |
ff05a229 | 737 | return enter_new_state(st,SITE_SENTMSG1); |
9d3a4132 | 738 | } |
ff05a229 | 739 | slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer"); |
9d3a4132 SE |
740 | return False; |
741 | } | |
742 | ||
2fe58dfd SE |
743 | static void activate_new_key(struct site *st) |
744 | { | |
745 | struct transform_inst_if *t; | |
746 | ||
ff05a229 SE |
747 | /* We have two transform instances, which we swap between active |
748 | and setup */ | |
2fe58dfd SE |
749 | t=st->current_transform; |
750 | st->current_transform=st->new_transform; | |
751 | st->new_transform=t; | |
752 | ||
753 | t->delkey(t->st); | |
2fe58dfd SE |
754 | st->timeout=0; |
755 | st->current_valid=True; | |
756 | st->current_key_timeout=st->now+st->key_lifetime; | |
ff05a229 | 757 | st->renegotiate_key_time=st->now+st->key_renegotiate_time; |
2fe58dfd SE |
758 | st->peer=st->setup_peer; |
759 | st->peer_valid=True; | |
760 | st->remote_session_id=st->setup_session_id; | |
761 | ||
762 | slog(st,LOG_ACTIVATE_KEY,"new key activated"); | |
9d3a4132 | 763 | enter_state_run(st); |
2fe58dfd SE |
764 | } |
765 | ||
fe5e9cc4 | 766 | static void delete_key(struct site *st, cstring_t reason, uint32_t loglevel) |
794f2398 SE |
767 | { |
768 | if (st->current_valid) { | |
769 | slog(st,loglevel,"session closed (%s)",reason); | |
770 | ||
771 | st->current_valid=False; | |
772 | st->current_transform->delkey(st->current_transform->st); | |
773 | st->current_key_timeout=0; | |
774 | set_link_quality(st); | |
775 | } | |
776 | } | |
777 | ||
2fe58dfd SE |
778 | static void state_assert(struct site *st, bool_t ok) |
779 | { | |
4f5e39ec | 780 | if (!ok) fatal("site:state_assert"); |
2fe58dfd SE |
781 | } |
782 | ||
783 | static void enter_state_stop(struct site *st) | |
784 | { | |
785 | st->state=SITE_STOP; | |
786 | st->timeout=0; | |
794f2398 | 787 | delete_key(st,"entering state STOP",LOG_TIMEOUT_KEY); |
2fe58dfd SE |
788 | st->new_transform->delkey(st->new_transform->st); |
789 | } | |
790 | ||
9d3a4132 SE |
791 | static void set_link_quality(struct site *st) |
792 | { | |
793 | uint32_t quality; | |
794 | if (st->current_valid) | |
795 | quality=LINK_QUALITY_UP; | |
796 | else if (st->state==SITE_WAIT || st->state==SITE_STOP) | |
797 | quality=LINK_QUALITY_DOWN; | |
798 | else if (st->address) | |
799 | quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS; | |
800 | else if (st->peer_valid) | |
801 | quality=LINK_QUALITY_DOWN_STALE_ADDRESS; | |
802 | else | |
803 | quality=LINK_QUALITY_DOWN; | |
804 | ||
469fd1d9 | 805 | st->netlink->set_quality(st->netlink->st,quality); |
9d3a4132 SE |
806 | } |
807 | ||
2fe58dfd SE |
808 | static void enter_state_run(struct site *st) |
809 | { | |
810 | slog(st,LOG_STATE,"entering state RUN"); | |
811 | st->state=SITE_RUN; | |
812 | st->timeout=0; | |
9d3a4132 | 813 | |
ff05a229 SE |
814 | st->setup_session_id=0; |
815 | memset(&st->setup_peer,0,sizeof(st->setup_peer)); | |
816 | memset(st->localN,0,NONCELEN); | |
817 | memset(st->remoteN,0,NONCELEN); | |
818 | st->new_transform->delkey(st->new_transform->st); | |
819 | memset(st->dhsecret,0,st->dh->len); | |
820 | memset(st->sharedsecret,0,st->transform->keylen); | |
9d3a4132 | 821 | set_link_quality(st); |
2fe58dfd SE |
822 | } |
823 | ||
824 | static bool_t enter_state_resolve(struct site *st) | |
825 | { | |
826 | state_assert(st,st->state==SITE_RUN); | |
827 | slog(st,LOG_STATE,"entering state RESOLVE"); | |
828 | st->state=SITE_RESOLVE; | |
829 | st->resolver->request(st->resolver->st,st->address, | |
830 | site_resolve_callback,st); | |
831 | return True; | |
832 | } | |
833 | ||
ff05a229 | 834 | static bool_t enter_new_state(struct site *st, uint32_t next) |
2fe58dfd | 835 | { |
ff05a229 | 836 | bool_t (*gen)(struct site *st); |
3b83c932 SE |
837 | int r; |
838 | ||
ff05a229 SE |
839 | slog(st,LOG_STATE,"entering state %s",state_name(next)); |
840 | switch(next) { | |
841 | case SITE_SENTMSG1: | |
842 | state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE); | |
843 | gen=generate_msg1; | |
844 | break; | |
845 | case SITE_SENTMSG2: | |
846 | state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE || | |
847 | st->state==SITE_SENTMSG1 || st->state==SITE_WAIT); | |
848 | gen=generate_msg2; | |
849 | break; | |
850 | case SITE_SENTMSG3: | |
851 | state_assert(st,st->state==SITE_SENTMSG1); | |
852 | BUF_FREE(&st->buffer); | |
853 | gen=generate_msg3; | |
854 | break; | |
855 | case SITE_SENTMSG4: | |
856 | state_assert(st,st->state==SITE_SENTMSG2); | |
857 | BUF_FREE(&st->buffer); | |
858 | gen=generate_msg4; | |
859 | break; | |
860 | case SITE_SENTMSG5: | |
861 | state_assert(st,st->state==SITE_SENTMSG3); | |
862 | BUF_FREE(&st->buffer); | |
863 | gen=generate_msg5; | |
864 | break; | |
865 | case SITE_RUN: | |
866 | state_assert(st,st->state==SITE_SENTMSG4); | |
867 | BUF_FREE(&st->buffer); | |
868 | gen=generate_msg6; | |
869 | break; | |
870 | default: | |
871 | gen=NULL; | |
4f5e39ec | 872 | fatal("enter_new_state(%s): invalid new state",state_name(next)); |
ff05a229 | 873 | break; |
2fe58dfd | 874 | } |
2fe58dfd | 875 | |
3b83c932 SE |
876 | if (hacky_par_start_failnow()) return False; |
877 | ||
878 | r= gen(st) && send_msg(st); | |
879 | ||
880 | hacky_par_end(&r, | |
881 | st->setup_retries, st->setup_timeout, | |
882 | send_msg, st); | |
883 | ||
884 | if (r) { | |
ff05a229 SE |
885 | st->state=next; |
886 | if (next==SITE_RUN) { | |
887 | BUF_FREE(&st->buffer); /* Never reused */ | |
888 | st->timeout=0; /* Never retransmit */ | |
889 | activate_new_key(st); | |
890 | } | |
2fe58dfd SE |
891 | return True; |
892 | } | |
ff05a229 SE |
893 | slog(st,LOG_ERROR,"error entering state %s",state_name(next)); |
894 | st->buffer.free=False; /* Unconditionally use the buffer; it may be | |
895 | in either state, and enter_state_wait() will | |
896 | do a BUF_FREE() */ | |
2fe58dfd SE |
897 | enter_state_wait(st); |
898 | return False; | |
899 | } | |
900 | ||
ff05a229 | 901 | /* msg7 tells our peer that we're about to forget our key */ |
fe5e9cc4 | 902 | static bool_t send_msg7(struct site *st, cstring_t reason) |
794f2398 | 903 | { |
fe5e9cc4 | 904 | cstring_t transform_err; |
794f2398 SE |
905 | |
906 | if (st->current_valid && st->peer_valid && st->buffer.free) { | |
907 | BUF_ALLOC(&st->buffer,"site:MSG7"); | |
908 | buffer_init(&st->buffer,st->transform->max_start_pad+(4*3)); | |
909 | buf_append_uint32(&st->buffer,LABEL_MSG7); | |
910 | buf_append_string(&st->buffer,reason); | |
911 | st->current_transform->forwards(st->current_transform->st, | |
912 | &st->buffer, &transform_err); | |
913 | buf_prepend_uint32(&st->buffer,LABEL_MSG0); | |
58650a70 | 914 | buf_prepend_uint32(&st->buffer,st->index); |
794f2398 SE |
915 | buf_prepend_uint32(&st->buffer,st->remote_session_id); |
916 | st->comm->sendmsg(st->comm->st,&st->buffer,&st->peer); | |
917 | BUF_FREE(&st->buffer); | |
918 | return True; | |
919 | } | |
920 | return False; | |
921 | } | |
922 | ||
2fe58dfd SE |
923 | /* We go into this state if our peer becomes uncommunicative. Similar to |
924 | the "stop" state, we forget all session keys for a while, before | |
925 | re-entering the "run" state. */ | |
926 | static void enter_state_wait(struct site *st) | |
927 | { | |
928 | slog(st,LOG_STATE,"entering state WAIT"); | |
929 | st->timeout=st->now+st->wait_timeout; | |
930 | st->state=SITE_WAIT; | |
931 | st->peer_valid=False; | |
9d3a4132 | 932 | set_link_quality(st); |
2fe58dfd SE |
933 | BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */ |
934 | /* XXX Erase keys etc. */ | |
935 | } | |
936 | ||
16f73fa6 | 937 | static inline void site_settimeout(uint64_t timeout, int *timeout_io) |
fe5e9cc4 SE |
938 | { |
939 | if (timeout) { | |
0009e60a IJ |
940 | int64_t offset=timeout-*now; |
941 | if (offset<0) offset=0; | |
fe5e9cc4 SE |
942 | if (offset>INT_MAX) offset=INT_MAX; |
943 | if (*timeout_io<0 || offset<*timeout_io) | |
944 | *timeout_io=offset; | |
945 | } | |
946 | } | |
947 | ||
2fe58dfd | 948 | static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io, |
90a39563 | 949 | int *timeout_io) |
2fe58dfd SE |
950 | { |
951 | struct site *st=sst; | |
952 | ||
953 | *nfds_io=0; /* We don't use any file descriptors */ | |
954 | st->now=*now; | |
955 | ||
956 | /* Work out when our next timeout is. The earlier of 'timeout' or | |
957 | 'current_key_timeout'. A stored value of '0' indicates no timeout | |
958 | active. */ | |
16f73fa6 IJ |
959 | site_settimeout(st->timeout, timeout_io); |
960 | site_settimeout(st->current_key_timeout, timeout_io); | |
2fe58dfd SE |
961 | |
962 | return 0; /* success */ | |
963 | } | |
964 | ||
965 | /* NB site_afterpoll will be called before site_beforepoll is ever called */ | |
90a39563 | 966 | static void site_afterpoll(void *sst, struct pollfd *fds, int nfds) |
2fe58dfd SE |
967 | { |
968 | struct site *st=sst; | |
969 | ||
970 | st->now=*now; | |
971 | if (st->timeout && *now>st->timeout) { | |
2fe58dfd | 972 | st->timeout=0; |
3b83c932 SE |
973 | if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) { |
974 | if (!hacky_par_start_failnow()) | |
975 | send_msg(st); | |
976 | } else if (st->state==SITE_WAIT) { | |
2fe58dfd SE |
977 | enter_state_run(st); |
978 | } else { | |
979 | slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d", | |
980 | st->state); | |
981 | } | |
982 | } | |
983 | if (st->current_key_timeout && *now>st->current_key_timeout) { | |
794f2398 | 984 | delete_key(st,"maximum key life exceeded",LOG_TIMEOUT_KEY); |
2fe58dfd SE |
985 | } |
986 | } | |
987 | ||
988 | /* This function is called by the netlink device to deliver packets | |
989 | intended for the remote network. The packet is in "raw" wire | |
990 | format, but is guaranteed to be word-aligned. */ | |
469fd1d9 | 991 | static void site_outgoing(void *sst, struct buffer_if *buf) |
2fe58dfd SE |
992 | { |
993 | struct site *st=sst; | |
fe5e9cc4 | 994 | cstring_t transform_err; |
2fe58dfd SE |
995 | |
996 | if (st->state==SITE_STOP) { | |
997 | BUF_FREE(buf); | |
998 | return; | |
999 | } | |
1000 | ||
1001 | /* In all other states we consider delivering the packet if we have | |
1002 | a valid key and a valid address to send it to. */ | |
1003 | if (st->current_valid && st->peer_valid) { | |
1004 | /* Transform it and send it */ | |
70dc107b SE |
1005 | if (buf->size>0) { |
1006 | buf_prepend_uint32(buf,LABEL_MSG9); | |
1007 | st->current_transform->forwards(st->current_transform->st, | |
1008 | buf, &transform_err); | |
1009 | buf_prepend_uint32(buf,LABEL_MSG0); | |
58650a70 | 1010 | buf_prepend_uint32(buf,st->index); |
70dc107b SE |
1011 | buf_prepend_uint32(buf,st->remote_session_id); |
1012 | st->comm->sendmsg(st->comm->st,buf,&st->peer); | |
1013 | } | |
2fe58dfd | 1014 | BUF_FREE(buf); |
ff05a229 SE |
1015 | /* See whether we should start negotiating a new key */ |
1016 | if (st->now > st->renegotiate_key_time) | |
1017 | initiate_key_setup(st,"outgoing packet in renegotiation window"); | |
2fe58dfd SE |
1018 | return; |
1019 | } | |
1020 | ||
70dc107b | 1021 | slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size); |
2fe58dfd | 1022 | BUF_FREE(buf); |
794f2398 | 1023 | initiate_key_setup(st,"outgoing packet"); |
2fe58dfd SE |
1024 | } |
1025 | ||
1026 | /* This function is called by the communication device to deliver | |
1027 | packets from our peers. */ | |
1028 | static bool_t site_incoming(void *sst, struct buffer_if *buf, | |
1029 | struct sockaddr_in *source) | |
1030 | { | |
1031 | struct site *st=sst; | |
59635212 | 1032 | uint32_t dest=ntohl(*(uint32_t *)buf->start); |
2fe58dfd SE |
1033 | |
1034 | if (dest==0) { | |
2fe58dfd SE |
1035 | /* It could be for any site - it should have LABEL_MSG1 and |
1036 | might have our name and our peer's name in it */ | |
ff05a229 | 1037 | if (buf->size<(st->setupsiglen+8+NONCELEN)) return False; |
2fe58dfd | 1038 | if (memcmp(buf->start+8,st->setupsig,st->setupsiglen)==0) { |
2fe58dfd | 1039 | /* It's addressed to us. Decide what to do about it. */ |
ff05a229 | 1040 | dump_packet(st,buf,source,True); |
2fe58dfd SE |
1041 | if (st->state==SITE_RUN || st->state==SITE_RESOLVE || |
1042 | st->state==SITE_WAIT) { | |
1043 | /* We should definitely process it */ | |
1044 | if (process_msg1(st,buf,source)) { | |
1045 | slog(st,LOG_SETUP_INIT,"key setup initiated by peer"); | |
ff05a229 | 1046 | enter_new_state(st,SITE_SENTMSG2); |
2fe58dfd SE |
1047 | } else { |
1048 | slog(st,LOG_ERROR,"failed to process incoming msg1"); | |
1049 | } | |
1050 | BUF_FREE(buf); | |
1051 | return True; | |
ff05a229 | 1052 | } else if (st->state==SITE_SENTMSG1) { |
2fe58dfd SE |
1053 | /* We've just sent a message 1! They may have crossed on |
1054 | the wire. If we have priority then we ignore the | |
1055 | incoming one, otherwise we process it as usual. */ | |
1056 | if (st->setup_priority) { | |
1057 | BUF_FREE(buf); | |
1058 | slog(st,LOG_DUMP,"crossed msg1s; we are higher " | |
1059 | "priority => ignore incoming msg1"); | |
1060 | return True; | |
1061 | } else { | |
1062 | slog(st,LOG_DUMP,"crossed msg1s; we are lower " | |
1063 | "priority => use incoming msg1"); | |
1064 | if (process_msg1(st,buf,source)) { | |
1065 | BUF_FREE(&st->buffer); /* Free our old message 1 */ | |
ff05a229 | 1066 | enter_new_state(st,SITE_SENTMSG2); |
2fe58dfd SE |
1067 | } else { |
1068 | slog(st,LOG_ERROR,"failed to process an incoming " | |
1069 | "crossed msg1 (we have low priority)"); | |
1070 | } | |
1071 | BUF_FREE(buf); | |
1072 | return True; | |
1073 | } | |
1074 | } | |
1075 | /* The message 1 was received at an unexpected stage of the | |
1076 | key setup. XXX POLICY - what do we do? */ | |
1077 | slog(st,LOG_UNEXPECTED,"unexpected incoming message 1"); | |
1078 | BUF_FREE(buf); | |
1079 | return True; | |
1080 | } | |
1081 | return False; /* Not for us. */ | |
1082 | } | |
58650a70 | 1083 | if (dest==st->index) { |
2fe58dfd | 1084 | /* Explicitly addressed to us */ |
ff05a229 | 1085 | uint32_t msgtype=ntohl(get_uint32(buf->start+8)); |
2fe58dfd SE |
1086 | if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True); |
1087 | switch (msgtype) { | |
794f2398 SE |
1088 | case 0: /* NAK */ |
1089 | /* If the source is our current peer then initiate a key setup, | |
1090 | because our peer's forgotten the key */ | |
1091 | if (get_uint32(buf->start+4)==st->remote_session_id) { | |
1092 | initiate_key_setup(st,"received a NAK"); | |
1093 | } else { | |
1094 | slog(st,LOG_SEC,"bad incoming NAK"); | |
1095 | } | |
1096 | break; | |
2fe58dfd SE |
1097 | case LABEL_MSG0: |
1098 | process_msg0(st,buf,source); | |
1099 | break; | |
1100 | case LABEL_MSG1: | |
1101 | /* Setup packet: should not have been explicitly addressed | |
1102 | to us */ | |
59635212 | 1103 | slog(st,LOG_SEC,"incoming explicitly addressed msg1"); |
2fe58dfd SE |
1104 | break; |
1105 | case LABEL_MSG2: | |
1106 | /* Setup packet: expected only in state SENTMSG1 */ | |
1107 | if (st->state!=SITE_SENTMSG1) { | |
1108 | slog(st,LOG_UNEXPECTED,"unexpected MSG2"); | |
1109 | } else if (process_msg2(st,buf,source)) | |
ff05a229 | 1110 | enter_new_state(st,SITE_SENTMSG3); |
2fe58dfd | 1111 | else { |
59635212 | 1112 | slog(st,LOG_SEC,"invalid MSG2"); |
2fe58dfd SE |
1113 | } |
1114 | break; | |
1115 | case LABEL_MSG3: | |
1116 | /* Setup packet: expected only in state SENTMSG2 */ | |
1117 | if (st->state!=SITE_SENTMSG2) { | |
1118 | slog(st,LOG_UNEXPECTED,"unexpected MSG3"); | |
1119 | } else if (process_msg3(st,buf,source)) | |
ff05a229 | 1120 | enter_new_state(st,SITE_SENTMSG4); |
2fe58dfd | 1121 | else { |
59635212 | 1122 | slog(st,LOG_SEC,"invalid MSG3"); |
2fe58dfd SE |
1123 | } |
1124 | break; | |
1125 | case LABEL_MSG4: | |
1126 | /* Setup packet: expected only in state SENTMSG3 */ | |
1127 | if (st->state!=SITE_SENTMSG3) { | |
1128 | slog(st,LOG_UNEXPECTED,"unexpected MSG4"); | |
1129 | } else if (process_msg4(st,buf,source)) | |
ff05a229 | 1130 | enter_new_state(st,SITE_SENTMSG5); |
2fe58dfd | 1131 | else { |
59635212 | 1132 | slog(st,LOG_SEC,"invalid MSG4"); |
2fe58dfd SE |
1133 | } |
1134 | break; | |
1135 | case LABEL_MSG5: | |
4efd681a SE |
1136 | /* Setup packet: expected only in state SENTMSG4 */ |
1137 | /* (may turn up in state RUN if our return MSG6 was lost | |
1138 | and the new key has already been activated. In that | |
1139 | case we should treat it as an ordinary PING packet. We | |
1140 | can't pass it to process_msg5() because the | |
ff05a229 | 1141 | new_transform will now be unkeyed. XXX) */ |
4efd681a | 1142 | if (st->state!=SITE_SENTMSG4) { |
2fe58dfd SE |
1143 | slog(st,LOG_UNEXPECTED,"unexpected MSG5"); |
1144 | } else if (process_msg5(st,buf,source)) { | |
ff05a229 | 1145 | enter_new_state(st,SITE_RUN); |
2fe58dfd | 1146 | } else { |
59635212 | 1147 | slog(st,LOG_SEC,"invalid MSG5"); |
2fe58dfd SE |
1148 | } |
1149 | break; | |
1150 | case LABEL_MSG6: | |
1151 | /* Setup packet: expected only in state SENTMSG5 */ | |
1152 | if (st->state!=SITE_SENTMSG5) { | |
1153 | slog(st,LOG_UNEXPECTED,"unexpected MSG6"); | |
1154 | } else if (process_msg6(st,buf,source)) { | |
1155 | BUF_FREE(&st->buffer); /* Free message 5 */ | |
1156 | activate_new_key(st); | |
1157 | } else { | |
59635212 | 1158 | slog(st,LOG_SEC,"invalid MSG6"); |
2fe58dfd SE |
1159 | } |
1160 | break; | |
2fe58dfd | 1161 | default: |
59635212 | 1162 | slog(st,LOG_SEC,"received message of unknown type 0x%08x", |
2fe58dfd SE |
1163 | msgtype); |
1164 | break; | |
1165 | } | |
1166 | BUF_FREE(buf); | |
1167 | return True; | |
1168 | } | |
1169 | ||
1170 | return False; | |
1171 | } | |
1172 | ||
1173 | static void site_control(void *vst, bool_t run) | |
1174 | { | |
1175 | struct site *st=vst; | |
1176 | if (run) enter_state_run(st); | |
1177 | else enter_state_stop(st); | |
1178 | } | |
1179 | ||
794f2398 SE |
1180 | static void site_phase_hook(void *sst, uint32_t newphase) |
1181 | { | |
1182 | struct site *st=sst; | |
1183 | ||
1184 | /* The program is shutting down; tell our peer */ | |
1185 | send_msg7(st,"shutting down"); | |
1186 | } | |
1187 | ||
2fe58dfd SE |
1188 | static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, |
1189 | list_t *args) | |
1190 | { | |
58650a70 | 1191 | static uint32_t index_sequence; |
2fe58dfd SE |
1192 | struct site *st; |
1193 | item_t *item; | |
1194 | dict_t *dict; | |
1195 | ||
1196 | st=safe_malloc(sizeof(*st),"site_apply"); | |
1197 | ||
1198 | st->cl.description="site"; | |
1199 | st->cl.type=CL_SITE; | |
1200 | st->cl.apply=NULL; | |
1201 | st->cl.interface=&st->ops; | |
1202 | st->ops.st=st; | |
1203 | st->ops.control=site_control; | |
1204 | st->ops.status=site_status; | |
1205 | ||
1206 | /* First parameter must be a dict */ | |
1207 | item=list_elem(args,0); | |
1208 | if (!item || item->type!=t_dict) | |
1209 | cfgfatal(loc,"site","parameter must be a dictionary\n"); | |
1210 | ||
1211 | dict=item->data.dict; | |
558fa3fb SE |
1212 | st->localname=dict_read_string(dict, "local-name", True, "site", loc); |
1213 | st->remotename=dict_read_string(dict, "name", True, "site", loc); | |
1214 | /* Sanity check (which also allows the 'sites' file to include | |
1215 | site() closures for all sites including our own): refuse to | |
1216 | talk to ourselves */ | |
1217 | if (strcmp(st->localname,st->remotename)==0) { | |
b2a56f7c | 1218 | Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n", |
baa06aeb | 1219 | st->localname); |
558fa3fb SE |
1220 | free(st); |
1221 | return NULL; | |
1222 | } | |
58650a70 RK |
1223 | assert(index_sequence < 0xffffffffUL); |
1224 | st->index = ++index_sequence; | |
469fd1d9 | 1225 | st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc); |
2fe58dfd SE |
1226 | st->comm=find_cl_if(dict,"comm",CL_COMM,True,"site",loc); |
1227 | st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc); | |
1228 | st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc); | |
1229 | st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc); | |
1230 | ||
2fe58dfd | 1231 | st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc); |
2fe58dfd | 1232 | st->address=dict_read_string(dict, "address", False, "site", loc); |
3454dce4 SE |
1233 | if (st->address) |
1234 | st->remoteport=dict_read_number(dict,"port",True,"site",loc,0); | |
1235 | else st->remoteport=0; | |
2fe58dfd SE |
1236 | st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc); |
1237 | ||
1238 | st->transform= | |
1239 | find_cl_if(dict,"transform",CL_TRANSFORM,True,"site",loc); | |
1240 | ||
1241 | st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc); | |
1242 | st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc); | |
1243 | ||
9d3a4132 SE |
1244 | st->key_lifetime=dict_read_number( |
1245 | dict,"key-lifetime",False,"site",loc,DEFAULT_KEY_LIFETIME); | |
9d3a4132 SE |
1246 | st->setup_retries=dict_read_number( |
1247 | dict,"setup-retries",False,"site",loc,DEFAULT_SETUP_RETRIES); | |
1248 | st->setup_timeout=dict_read_number( | |
1249 | dict,"setup-timeout",False,"site",loc,DEFAULT_SETUP_TIMEOUT); | |
1250 | st->wait_timeout=dict_read_number( | |
1251 | dict,"wait-time",False,"site",loc,DEFAULT_WAIT_TIME); | |
c27ca22f IJ |
1252 | |
1253 | if (st->key_lifetime < DEFAULT_KEY_RENEGOTIATE_GAP*2) | |
1254 | st->key_renegotiate_time=st->key_lifetime/2; | |
1255 | else | |
1256 | st->key_renegotiate_time=st->key_lifetime-DEFAULT_KEY_RENEGOTIATE_GAP; | |
9d3a4132 | 1257 | st->key_renegotiate_time=dict_read_number( |
cce0051f | 1258 | dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time); |
9d3a4132 SE |
1259 | if (st->key_renegotiate_time > st->key_lifetime) { |
1260 | cfgfatal(loc,"site", | |
1261 | "renegotiate-time must be less than key-lifetime\n"); | |
1262 | } | |
9d3a4132 SE |
1263 | st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False); |
1264 | ||
1265 | st->log_events=string_list_to_word(dict_lookup(dict,"log-events"), | |
1266 | log_event_table,"site"); | |
2fe58dfd | 1267 | |
4efd681a SE |
1268 | st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5, |
1269 | "site_apply"); | |
1270 | sprintf(st->tunname,"%s<->%s",st->localname,st->remotename); | |
1271 | ||
2fe58dfd | 1272 | /* The information we expect to see in incoming messages of type 1 */ |
59230b9b IJ |
1273 | /* fixme: lots of unchecked overflows here, but the results are only |
1274 | corrupted packets rather than undefined behaviour */ | |
2fe58dfd SE |
1275 | st->setupsiglen=strlen(st->remotename)+strlen(st->localname)+8; |
1276 | st->setupsig=safe_malloc(st->setupsiglen,"site_apply"); | |
8689b3a9 SE |
1277 | put_uint32(st->setupsig+0,LABEL_MSG1); |
1278 | put_uint16(st->setupsig+4,strlen(st->remotename)); | |
2fe58dfd | 1279 | memcpy(&st->setupsig[6],st->remotename,strlen(st->remotename)); |
8689b3a9 | 1280 | put_uint16(st->setupsig+(6+strlen(st->remotename)),strlen(st->localname)); |
2fe58dfd SE |
1281 | memcpy(&st->setupsig[8+strlen(st->remotename)],st->localname, |
1282 | strlen(st->localname)); | |
1283 | st->setup_priority=(strcmp(st->localname,st->remotename)>0); | |
1284 | ||
1285 | buffer_new(&st->buffer,SETUP_BUFFER_LEN); | |
1286 | ||
1287 | /* We are interested in poll(), but only for timeouts. We don't have | |
1288 | any fds of our own. */ | |
1289 | register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site"); | |
1290 | st->timeout=0; | |
1291 | ||
1292 | st->current_valid=False; | |
1293 | st->current_key_timeout=0; | |
1294 | st->peer_valid=False; | |
1295 | /* XXX mlock these */ | |
1296 | st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret"); | |
1297 | st->sharedsecret=safe_malloc(st->transform->keylen,"site:sharedsecret"); | |
1298 | ||
1299 | /* We need to register the remote networks with the netlink device */ | |
469fd1d9 | 1300 | st->netlink->reg(st->netlink->st, site_outgoing, st, |
ff05a229 SE |
1301 | st->transform->max_start_pad+(4*4)+ |
1302 | st->comm->min_start_pad, | |
1303 | st->transform->max_end_pad+st->comm->min_end_pad); | |
1304 | ||
2fe58dfd SE |
1305 | st->comm->request_notify(st->comm->st, st, site_incoming); |
1306 | ||
1307 | st->current_transform=st->transform->create(st->transform->st); | |
1308 | st->new_transform=st->transform->create(st->transform->st); | |
1309 | ||
1310 | enter_state_stop(st); | |
1311 | ||
794f2398 SE |
1312 | add_hook(PHASE_SHUTDOWN,site_phase_hook,st); |
1313 | ||
2fe58dfd SE |
1314 | return new_closure(&st->cl); |
1315 | } | |
1316 | ||
2fe58dfd SE |
1317 | void site_module(dict_t *dict) |
1318 | { | |
1319 | add_closure(dict,"site",site_apply); | |
1320 | } |