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Comparing gvpe/src/protocol.C (file contents):
Revision 1.14 by pcg, Sat Mar 22 22:39:11 2003 UTC vs.
Revision 1.17 by pcg, Wed Mar 26 01:58:46 2003 UTC

… …
58 58
59static time_t next_timecheck; 59static time_t next_timecheck;
60 60
61#define MAGIC "vped\xbd\xc6\xdb\x82" // 8 bytes of magic 61#define MAGIC "vped\xbd\xc6\xdb\x82" // 8 bytes of magic
62 62
63static const rsachallenge & 63struct crypto_ctx
64challenge_bytes ()
65{
66 static rsachallenge challenge;
67 static double challenge_ttl; // time this challenge needs to be recreated
68
69 if (NOW > challenge_ttl)
70 { 64 {
71 RAND_bytes ((unsigned char *)&challenge, sizeof (challenge)); 65 EVP_CIPHER_CTX cctx;
72 challenge_ttl = NOW + CHALLENGE_TTL; 66 HMAC_CTX hctx;
73 }
74 67
75 return challenge; 68 crypto_ctx (const rsachallenge &challenge, int enc);
76} 69 ~crypto_ctx ();
70 };
77 71
78// caching of rsa operations really helps slow computers 72crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc)
73{
74 EVP_CIPHER_CTX_init (&cctx);
75 EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc);
76 HMAC_CTX_init (&hctx);
77 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
78}
79
80crypto_ctx::~crypto_ctx ()
81{
82 EVP_CIPHER_CTX_cleanup (&cctx);
83 HMAC_CTX_cleanup (&hctx);
84}
85
86static void
87rsa_hash (const rsachallenge &chg, rsaresponse &h)
88{
89 EVP_MD_CTX ctx;
90
91 EVP_MD_CTX_init (&ctx);
92 EVP_DigestInit (&ctx, RSA_HASH);
93 EVP_DigestUpdate(&ctx, &chg, sizeof chg);
94 EVP_DigestFinal (&ctx, (unsigned char *)&h, 0);
95 EVP_MD_CTX_cleanup (&ctx);
96}
97
79struct rsa_entry { 98struct rsa_entry {
80 tstamp expire; 99 tstamp expire;
100 rsaid id;
81 rsachallenge chg; 101 rsachallenge chg;
82 RSA *key; // which key
83 rsaencrdata encr;
84
85 rsa_entry ()
86 {
87 expire = NOW + CHALLENGE_TTL;
88 }
89}; 102};
90 103
91struct rsa_cache : list<rsa_entry> 104struct rsa_cache : list<rsa_entry>
92{ 105{
93 void cleaner_cb (tstamp &ts); time_watcher cleaner; 106 void cleaner_cb (tstamp &ts); time_watcher cleaner;
94 107
95 const rsaencrdata *public_encrypt (RSA *key, const rsachallenge &chg) 108 bool find (const rsaid &id, rsachallenge &chg)
96 { 109 {
97 for (iterator i = begin (); i != end (); ++i) 110 for (iterator i = begin (); i != end (); ++i)
98 { 111 {
99 if (i->key == key && !memcmp (&chg, &i->chg, sizeof chg)) 112 if (!memcmp (&id, &i->id, sizeof id) && i->expire > NOW)
100 return &i->encr; 113 {
114 memcpy (&chg, &i->chg, sizeof chg);
115
116 erase (i);
117 return true;
118 }
101 } 119 }
102 120
103 if (cleaner.at < NOW) 121 if (cleaner.at < NOW)
104 cleaner.start (NOW + CHALLENGE_TTL); 122 cleaner.start (NOW + RSA_TTL);
105 123
106 resize (size () + 1); 124 return false;
107 rsa_entry *e = &(*rbegin ()); 125 }
108 126
109 e->key = key; 127 void gen (rsaid &id, rsachallenge &chg)
128 {
129 rsa_entry e;
130
131 RAND_bytes ((unsigned char *)&id, sizeof id);
132 RAND_bytes ((unsigned char *)&chg, sizeof chg);
133
134 e.expire = NOW + RSA_TTL;
135 e.id = id;
110 memcpy (&e->chg, &chg, sizeof chg); 136 memcpy (&e.chg, &chg, sizeof chg);
111 137
112 if (0 > RSA_public_encrypt (sizeof chg, 138 push_back (e);
113 (unsigned char *)&chg, (unsigned char *)&e->encr,
114 key, RSA_PKCS1_OAEP_PADDING))
115 fatal ("RSA_public_encrypt error");
116
117 return &e->encr;
118 }
119
120 const rsachallenge *private_decrypt (RSA *key, const rsaencrdata &encr)
121 {
122 for (iterator i = begin (); i != end (); ++i)
123 if (i->key == key && !memcmp (&encr, &i->encr, sizeof encr))
124 return &i->chg;
125 139
126 if (cleaner.at < NOW) 140 if (cleaner.at < NOW)
127 cleaner.start (NOW + CHALLENGE_TTL); 141 cleaner.start (NOW + RSA_TTL);
128
129 resize (size () + 1);
130 rsa_entry *e = &(*rbegin ());
131
132 e->key = key;
133 memcpy (&e->encr, &encr, sizeof encr);
134
135 if (0 > RSA_private_decrypt (sizeof encr,
136 (unsigned char *)&encr, (unsigned char *)&e->chg,
137 key, RSA_PKCS1_OAEP_PADDING))
138 {
139 pop_back ();
140 return 0;
141 }
142
143 return &e->chg;
144 } 142 }
145 143
146 rsa_cache () 144 rsa_cache ()
147 : cleaner (this, &rsa_cache::cleaner_cb) 145 : cleaner (this, &rsa_cache::cleaner_cb)
148 { } 146 { }
… …
153{ 151{
154 if (empty ()) 152 if (empty ())
155 ts = TSTAMP_CANCEL; 153 ts = TSTAMP_CANCEL;
156 else 154 else
157 { 155 {
158 ts = NOW + 3; 156 ts = NOW + RSA_TTL;
157
159 for (iterator i = begin (); i != end (); ) 158 for (iterator i = begin (); i != end (); )
160 {
161 if (i->expire >= NOW) 159 if (i->expire <= NOW)
162 i = erase (i); 160 i = erase (i);
163 else 161 else
164 ++i; 162 ++i;
165 }
166 } 163 }
167} 164}
168 165
169// run a script. yes, it's a template function. yes, c++ 166typedef callback<const char *, int> run_script_cb;
170// is not a functional language. yes, this suxx. 167
171template<class owner> 168// run a shell script (or actually an external program).
172static void 169static void
173run_script (owner *obj, const char *(owner::*setup)(), bool wait) 170run_script (const run_script_cb &cb, bool wait)
174{ 171{
175 int pid; 172 int pid;
176 173
177 if ((pid = fork ()) == 0) 174 if ((pid = fork ()) == 0)
178 { 175 {
179 char *filename; 176 char *filename;
180 asprintf (&filename, "%s/%s", confbase, (obj->*setup) ()); 177 asprintf (&filename, "%s/%s", confbase, cb(0));
181 execl (filename, filename, (char *) 0); 178 execl (filename, filename, (char *) 0);
182 exit (255); 179 exit (255);
183 } 180 }
184 else if (pid > 0) 181 else if (pid > 0)
185 { 182 {
… …
189 /* TODO: check status */ 186 /* TODO: check status */
190 } 187 }
191 } 188 }
192} 189}
193 190
194// xor the socket address into the challenge to ensure different challenges
195// per host. we could rely on the OAEP padding, but this doesn't hurt.
196void
197xor_sa (rsachallenge &k, SOCKADDR *sa)
198{
199 ((u32 *) k)[(CHG_CIPHER_KEY + 0) / 4] ^= sa->sin_addr.s_addr;
200 ((u16 *) k)[(CHG_CIPHER_KEY + 4) / 2] ^= sa->sin_port;
201 ((u32 *) k)[(CHG_HMAC_KEY + 0) / 4] ^= sa->sin_addr.s_addr;
202 ((u16 *) k)[(CHG_HMAC_KEY + 4) / 2] ^= sa->sin_port;
203}
204
205struct crypto_ctx
206 {
207 EVP_CIPHER_CTX cctx;
208 HMAC_CTX hctx;
209
210 crypto_ctx (const rsachallenge &challenge, int enc);
211 ~crypto_ctx ();
212 };
213
214crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc)
215{
216 EVP_CIPHER_CTX_init (&cctx);
217 EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc);
218 HMAC_CTX_init (&hctx);
219 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
220}
221
222crypto_ctx::~crypto_ctx ()
223{
224 EVP_CIPHER_CTX_cleanup (&cctx);
225 HMAC_CTX_cleanup (&hctx);
226}
227
228////////////////////////////////////////////////////////////////////////////// 191//////////////////////////////////////////////////////////////////////////////
229 192
230void pkt_queue::put (tap_packet *p) 193void pkt_queue::put (tap_packet *p)
231{ 194{
232 if (queue[i]) 195 if (queue[i])
… …
264{ 227{
265 for (i = QUEUEDEPTH; --i > 0; ) 228 for (i = QUEUEDEPTH; --i > 0; )
266 delete queue[i]; 229 delete queue[i];
267} 230}
268 231
232struct net_rateinfo {
233 u32 host;
234 double pcnt, diff;
235 tstamp last;
236};
237
269// only do action once every x seconds per host. 238// only do action once every x seconds per host whole allowing bursts.
270// currently this is quite a slow implementation, 239// this implementation ("splay list" ;) is inefficient,
271// but suffices for normal operation. 240// but low on resources.
272struct u32_rate_limiter : private map<u32, tstamp> 241struct net_rate_limiter : private list<net_rateinfo>
273 { 242{
274 tstamp every; 243 static const double ALPHA = 1. - 1. / 90.; // allow bursts
244 static const double CUTOFF = 20.; // one event every CUTOFF seconds
245 static const double EXPIRE = CUTOFF * 30.; // expire entries after this time
275 246
276 bool can (u32 host); 247 bool can (u32 host);
277
278 u32_rate_limiter (tstamp every = 1)
279 {
280 this->every = every;
281 }
282 };
283
284struct net_rate_limiter : u32_rate_limiter
285 {
286 bool can (SOCKADDR *sa) { return u32_rate_limiter::can((u32)sa->sin_addr.s_addr); } 248 bool can (SOCKADDR *sa) { return can((u32)sa->sin_addr.s_addr); }
287 bool can (sockinfo &si) { return u32_rate_limiter::can((u32)si.host); } 249 bool can (sockinfo &si) { return can((u32)si.host); }
250};
288 251
289 net_rate_limiter (tstamp every) : u32_rate_limiter (every) {} 252net_rate_limiter auth_rate_limiter, reset_rate_limiter;
290 };
291 253
292bool u32_rate_limiter::can (u32 host) 254bool net_rate_limiter::can (u32 host)
293{ 255{
294 iterator i; 256 iterator i;
295 257
296 for (i = begin (); i != end (); ) 258 for (i = begin (); i != end (); )
297 if (i->second <= NOW) 259 if (i->host == host)
298 { 260 break;
261 else if (i->last < NOW - EXPIRE)
299 erase (i); 262 i = erase (i);
300 i = begin ();
301 }
302 else 263 else
303 ++i; 264 i++;
304 265
305 i = find (host);
306
307 if (i != end ()) 266 if (i == end ())
308 return false; 267 {
268 net_rateinfo ri;
309 269
310 insert (value_type (host, NOW + every)); 270 ri.host = host;
271 ri.pcnt = 1.;
272 ri.diff = CUTOFF * (1. / (1. - ALPHA));
273 ri.last = NOW;
311 274
275 push_front (ri);
276
312 return true; 277 return true;
278 }
279 else
280 {
281 net_rateinfo ri (*i);
282 erase (i);
283
284 ri.pcnt = ri.pcnt * ALPHA;
285 ri.diff = ri.diff * ALPHA + (NOW - ri.last);
286
287 ri.last = NOW;
288
289 bool send = ri.diff / ri.pcnt > CUTOFF;
290
291 if (send)
292 ri.pcnt++;
293
294 //printf ("RATE %d %f,%f = %f > %f\n", !!send, ri.pcnt, ri.diff, ri.diff / ri.pcnt, CUTOFF);
295
296 push_front (ri);
297
298 return send;
299 }
313} 300}
314 301
315///////////////////////////////////////////////////////////////////////////// 302/////////////////////////////////////////////////////////////////////////////
316 303
317static void next_wakeup (time_t next) 304static void next_wakeup (time_t next)
… …
364 { 351 {
365 PT_RESET = 0, 352 PT_RESET = 0,
366 PT_DATA_UNCOMPRESSED, 353 PT_DATA_UNCOMPRESSED,
367 PT_DATA_COMPRESSED, 354 PT_DATA_COMPRESSED,
368 PT_PING, PT_PONG, // wasting namespace space? ;) 355 PT_PING, PT_PONG, // wasting namespace space? ;)
369 PT_AUTH, // authentification 356 PT_AUTH_REQ, // authentification request
357 PT_AUTH_RES, // authentification response
370 PT_CONNECT_REQ, // want other host to contact me 358 PT_CONNECT_REQ, // want other host to contact me
371 PT_CONNECT_INFO, // request connection to some node 359 PT_CONNECT_INFO, // request connection to some node
372 PT_REKEY, // rekeying (not yet implemented)
373 PT_MAX 360 PT_MAX
374 }; 361 };
375 362
376 u8 type; 363 u8 type;
377 u8 srcdst, src1, dst1; 364 u8 srcdst, src1, dst1;
… …
525 512
526 return p; 513 return p;
527} 514}
528 515
529struct ping_packet : vpn_packet 516struct ping_packet : vpn_packet
517{
518 void setup (int dst, ptype type)
530 { 519 {
531 void setup (int dst, ptype type)
532 {
533 set_hdr (type, dst); 520 set_hdr (type, dst);
534 len = sizeof (*this) - sizeof (net_packet); 521 len = sizeof (*this) - sizeof (net_packet);
535 }
536 }; 522 }
523};
537 524
538struct config_packet : vpn_packet 525struct config_packet : vpn_packet
526{
527 // actually, hmaclen cannot be checked because the hmac
528 // field comes before this data, so peers with other
529 // hmacs simply will not work.
530 u8 prot_major, prot_minor, randsize, hmaclen;
531 u8 flags, challengelen, pad2, pad3;
532 u32 cipher_nid, digest_nid, hmac_nid;
533
534 const u8 curflags () const
539 { 535 {
540 // actually, hmaclen cannot be checked because the hmac
541 // field comes before this data, so peers with other
542 // hmacs simply will not work.
543 u8 prot_major, prot_minor, randsize, hmaclen;
544 u8 flags, challengelen, pad2, pad3;
545 u32 cipher_nid;
546 u32 digest_nid;
547
548 const u8 curflags () const
549 {
550 return 0x80 536 return 0x80
551 | (ENABLE_COMPRESSION ? 0x01 : 0x00); 537 | (ENABLE_COMPRESSION ? 0x01 : 0x00);
552 } 538 }
553 539
554 void setup (ptype type, int dst) 540 void setup (ptype type, int dst)
555 {
556 prot_major = PROTOCOL_MAJOR;
557 prot_minor = PROTOCOL_MINOR;
558 randsize = RAND_SIZE;
559 hmaclen = HMACLENGTH;
560 flags = curflags ();
561 challengelen = sizeof (rsachallenge);
562
563 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER));
564 digest_nid = htonl (EVP_MD_type (DIGEST));
565
566 len = sizeof (*this) - sizeof (net_packet);
567 set_hdr (type, dst);
568 }
569
570 bool chk_config ()
571 {
572 return prot_major == PROTOCOL_MAJOR
573 && randsize == RAND_SIZE
574 && hmaclen == HMACLENGTH
575 && flags == curflags ()
576 && challengelen == sizeof (rsachallenge)
577 && cipher_nid == htonl (EVP_CIPHER_nid (CIPHER))
578 && digest_nid == htonl (EVP_MD_type (DIGEST));
579 }
580 };
581
582struct auth_packet : config_packet
583 { 541 {
584 char magic[8]; 542 prot_major = PROTOCOL_MAJOR;
585 u8 subtype; 543 prot_minor = PROTOCOL_MINOR;
586 u8 pad1, pad2; 544 randsize = RAND_SIZE;
587 rsaencrdata challenge; 545 hmaclen = HMACLENGTH;
546 flags = curflags ();
547 challengelen = sizeof (rsachallenge);
588 548
589 auth_packet (int dst, auth_subtype stype) 549 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER));
590 { 550 digest_nid = htonl (EVP_MD_type (RSA_HASH));
591 config_packet::setup (PT_AUTH, dst); 551 hmac_nid = htonl (EVP_MD_type (DIGEST));
592 subtype = stype; 552
593 len = sizeof (*this) - sizeof (net_packet); 553 len = sizeof (*this) - sizeof (net_packet);
554 set_hdr (type, dst);
555 }
556
557 bool chk_config ()
558 {
559 return prot_major == PROTOCOL_MAJOR
560 && randsize == RAND_SIZE
561 && hmaclen == HMACLENGTH
562 && flags == curflags ()
563 && challengelen == sizeof (rsachallenge)
564 && cipher_nid == htonl (EVP_CIPHER_nid (CIPHER))
565 && digest_nid == htonl (EVP_MD_type (RSA_HASH))
566 && hmac_nid == htonl (EVP_MD_type (DIGEST));
567 }
568};
569
570struct auth_req_packet : config_packet
571{
572 char magic[8];
573 u8 initiate; // false if this is just an automatic reply
574 u8 pad1, pad2, pad3;
575 rsaid id;
576 rsaencrdata encr;
577
578 auth_req_packet (int dst, bool initiate_)
579 {
580 config_packet::setup (PT_AUTH_REQ, dst);
581 initiate = !!initiate_;
594 strncpy (magic, MAGIC, 8); 582 strncpy (magic, MAGIC, 8);
595 } 583 len = sizeof (*this) - sizeof (net_packet);
596 }; 584 }
585};
586
587struct auth_res_packet : config_packet
588{
589 rsaid id;
590 rsaresponse response;
591
592 auth_res_packet (int dst)
593 {
594 config_packet::setup (PT_AUTH_RES, dst);
595 len = sizeof (*this) - sizeof (net_packet);
596 }
597};
597 598
598struct connect_req_packet : vpn_packet 599struct connect_req_packet : vpn_packet
600{
601 u8 id;
602 u8 pad1, pad2, pad3;
603
604 connect_req_packet (int dst, int id_)
599 { 605 {
600 u8 id; 606 id = id_;
601 u8 pad1, pad2, pad3;
602
603 connect_req_packet (int dst, int id)
604 {
605 this->id = id;
606 set_hdr (PT_CONNECT_REQ, dst); 607 set_hdr (PT_CONNECT_REQ, dst);
607 len = sizeof (*this) - sizeof (net_packet); 608 len = sizeof (*this) - sizeof (net_packet);
608 }
609 }; 609 }
610};
610 611
611struct connect_info_packet : vpn_packet 612struct connect_info_packet : vpn_packet
613{
614 u8 id;
615 u8 pad1, pad2, pad3;
616 sockinfo si;
617
618 connect_info_packet (int dst, int id_, sockinfo &si_)
612 { 619 {
613 u8 id; 620 id = id_;
614 u8 pad1, pad2, pad3; 621 si = si_;
615 sockinfo si;
616
617 connect_info_packet (int dst, int id, sockinfo &si)
618 {
619 this->id = id;
620 this->si = si;
621 set_hdr (PT_CONNECT_INFO, dst); 622 set_hdr (PT_CONNECT_INFO, dst);
622 len = sizeof (*this) - sizeof (net_packet); 623 len = sizeof (*this) - sizeof (net_packet);
623 }
624 }; 624 }
625};
625 626
626///////////////////////////////////////////////////////////////////////////// 627/////////////////////////////////////////////////////////////////////////////
627 628
628void 629void
629fill_sa (SOCKADDR *sa, conf_node *conf) 630fill_sa (SOCKADDR *sa, conf_node *conf)
… …
665} 666}
666 667
667void 668void
668connection::send_reset (SOCKADDR *dsa) 669connection::send_reset (SOCKADDR *dsa)
669{ 670{
670 static net_rate_limiter limiter(1);
671
672 if (limiter.can (dsa) && connectmode != conf_node::C_DISABLED) 671 if (reset_rate_limiter.can (dsa) && connectmode != conf_node::C_DISABLED)
673 { 672 {
674 config_packet *pkt = new config_packet; 673 config_packet *pkt = new config_packet;
675 674
676 pkt->setup (vpn_packet::PT_RESET, conf->id); 675 pkt->setup (vpn_packet::PT_RESET, conf->id);
677 vpn->send_vpn_packet (pkt, dsa, IPTOS_MINCOST); 676 vpn->send_vpn_packet (pkt, dsa, IPTOS_MINCOST);
678 677
679 delete pkt; 678 delete pkt;
680 } 679 }
681} 680}
682 681
683static rsachallenge *
684gen_challenge (u32 seqrand, SOCKADDR *sa)
685{
686 static rsachallenge k;
687
688 memcpy (&k, &challenge_bytes (), sizeof (k));
689 *(u32 *)&k[CHG_SEQNO] ^= seqrand;
690 xor_sa (k, sa);
691
692 return &k;
693}
694
695void 682void
696connection::send_auth (auth_subtype subtype, SOCKADDR *sa, const rsachallenge *k) 683connection::send_auth_request (SOCKADDR *sa, bool initiate)
697{ 684{
698 static net_rate_limiter limiter(0.2); 685 if (auth_rate_limiter.can (sa))
699
700 if (subtype != AUTH_INIT || limiter.can (sa))
701 { 686 {
702 if (!k)
703 k = gen_challenge (seqrand, sa);
704
705 auth_packet *pkt = new auth_packet (conf->id, subtype); 687 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate);
706 688
707 memcpy (pkt->challenge, rsa_cache.public_encrypt (conf->rsa_key, *k), sizeof (rsaencrdata)); 689 rsachallenge chg;
708 690
691 rsa_cache.gen (pkt->id, chg);
692
693 if (0 > RSA_public_encrypt (sizeof chg,
694 (unsigned char *)&chg, (unsigned char *)&pkt->encr,
695 conf->rsa_key, RSA_PKCS1_OAEP_PADDING))
696 fatal ("RSA_public_encrypt error");
697
709 slog (L_TRACE, ">>%d PT_AUTH(%d) [%s]", conf->id, subtype, (const char *)sockinfo (sa)); 698 slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)sockinfo (sa));
710 699
711 vpn->send_vpn_packet (pkt, sa, IPTOS_RELIABILITY); 700 vpn->send_vpn_packet (pkt, sa, IPTOS_RELIABILITY); // rsa is very very costly
701
702 delete pkt;
703 }
704}
705
706void
707connection::send_auth_response (SOCKADDR *sa, const rsaid &id, const rsachallenge &chg)
708{
709 if (auth_rate_limiter.can (sa))
710 {
711 auth_res_packet *pkt = new auth_res_packet (conf->id);
712
713 pkt->id = id;
714 rsa_hash (chg, pkt->response);
715
716 slog (L_TRACE, ">>%d PT_AUTH_RES [%s]", conf->id, (const char *)sockinfo (sa));
717
718 vpn->send_vpn_packet (pkt, sa, IPTOS_RELIABILITY); // rsa is very very costly
712 719
713 delete pkt; 720 delete pkt;
714 } 721 }
715} 722}
716 723
… …
719{ 726{
720 if (ictx || conf == THISNODE || connectmode == conf_node::C_NEVER) 727 if (ictx || conf == THISNODE || connectmode == conf_node::C_NEVER)
721 ts = TSTAMP_CANCEL; 728 ts = TSTAMP_CANCEL;
722 else if (ts <= NOW) 729 else if (ts <= NOW)
723 { 730 {
724 double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.25; 731 double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.6;
725 732
726 if (retry_int < 3600 * 8) 733 if (retry_int < 3600 * 8)
727 retry_cnt++; 734 retry_cnt++;
728
729 if (connectmode == conf_node::C_ONDEMAND
730 && retry_int > ::conf.keepalive)
731 retry_int = ::conf.keepalive;
732 735
733 ts = NOW + retry_int; 736 ts = NOW + retry_int;
734 737
735 if (conf->hostname) 738 if (conf->hostname)
736 { 739 {
737 reset_dstaddr (); 740 reset_dstaddr ();
738 if (sa.sin_addr.s_addr) 741 if (sa.sin_addr.s_addr)
739 if (retry_cnt < 4) 742 if (retry_cnt < 4)
740 send_auth (AUTH_INIT, &sa); 743 send_auth_request (&sa, true);
741 else 744 else if (auth_rate_limiter.can (&sa))
742 send_ping (&sa, 0); 745 send_ping (&sa, 0);
743 } 746 }
744 else 747 else
745 vpn->connect_request (conf->id); 748 vpn->connect_request (conf->id);
746 } 749 }
… …
752 if (ictx && octx) 755 if (ictx && octx)
753 { 756 {
754 slog (L_INFO, _("connection to %d (%s) lost"), conf->id, conf->nodename); 757 slog (L_INFO, _("connection to %d (%s) lost"), conf->id, conf->nodename);
755 758
756 if (::conf.script_node_down) 759 if (::conf.script_node_down)
757 run_script (this, &connection::script_node_down, false); 760 run_script (run_script_cb (this, &connection::script_node_down), false);
758 } 761 }
759 762
760 delete ictx; ictx = 0; 763 delete ictx; ictx = 0;
761 delete octx; octx = 0; 764 delete octx; octx = 0;
762
763 RAND_bytes ((unsigned char *)&seqrand, sizeof (u32));
764 765
765 sa.sin_port = 0; 766 sa.sin_port = 0;
766 sa.sin_addr.s_addr = 0; 767 sa.sin_addr.s_addr = 0;
767 768
768 last_activity = 0; 769 last_activity = 0;
… …
833 conf->id, pkt->typ (), pkt->src (), pkt->dst ()); 834 conf->id, pkt->typ (), pkt->src (), pkt->dst ());
834 835
835 switch (pkt->typ ()) 836 switch (pkt->typ ())
836 { 837 {
837 case vpn_packet::PT_PING: 838 case vpn_packet::PT_PING:
838 send_ping (ssa, 1); // pong
839 break;
840
841 case vpn_packet::PT_PONG:
842 // we send pings instead of auth packets after some retries, 839 // we send pings instead of auth packets after some retries,
843 // so reset the retry counter and establish a conenction 840 // so reset the retry counter and establish a conenction
844 // when we receive a pong. 841 // when we receive a pong.
845 if (!ictx && !octx) 842 if (!ictx && !octx)
846 { 843 {
847 retry_cnt = 0; 844 retry_cnt = 0;
848 establish_connection.at = 0; 845 establish_connection.at = 0;
849 establish_connection (); 846 establish_connection ();
850 } 847 }
848 else
849 send_ping (ssa, 1); // pong
851 850
851 break;
852
853 case vpn_packet::PT_PONG:
852 break; 854 break;
853 855
854 case vpn_packet::PT_RESET: 856 case vpn_packet::PT_RESET:
855 { 857 {
856 reset_connection (); 858 reset_connection ();
857 859
858 config_packet *p = (config_packet *) pkt; 860 config_packet *p = (config_packet *) pkt;
861
859 if (!p->chk_config ()) 862 if (!p->chk_config ())
860 { 863 {
861 slog (L_WARN, _("protocol mismatch, disabling node '%s'"), conf->nodename); 864 slog (L_WARN, _("protocol mismatch, disabling node '%s'"), conf->nodename);
862 connectmode = conf_node::C_DISABLED; 865 connectmode = conf_node::C_DISABLED;
863 } 866 }
864 else if (connectmode == conf_node::C_ALWAYS) 867 else if (connectmode == conf_node::C_ALWAYS)
865 establish_connection (); 868 establish_connection ();
866 } 869 }
867 break; 870 break;
868 871
869 case vpn_packet::PT_AUTH: 872 case vpn_packet::PT_AUTH_REQ:
870 { 873 {
871 auth_packet *p = (auth_packet *) pkt; 874 auth_req_packet *p = (auth_req_packet *) pkt;
872 875
873 slog (L_TRACE, "<<%d PT_AUTH(%d)", conf->id, p->subtype); 876 slog (L_TRACE, "<<%d PT_AUTH_REQ(%d)", conf->id, p->initiate);
874 877
875 if (p->chk_config ()
876 && !strncmp (p->magic, MAGIC, 8)) 878 if (p->chk_config () && !strncmp (p->magic, MAGIC, 8))
877 { 879 {
878 if (p->prot_minor != PROTOCOL_MINOR) 880 if (p->prot_minor != PROTOCOL_MINOR)
879 slog (L_INFO, _("protocol minor version mismatch: ours is %d, %s's is %d."), 881 slog (L_INFO, _("protocol minor version mismatch: ours is %d, %s's is %d."),
880 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 882 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
881 883
882 if (p->subtype == AUTH_INIT) 884 if (p->initiate)
883 send_auth (AUTH_INITREPLY, ssa); 885 send_auth_request (ssa, false);
884 886
885 const rsachallenge *k = rsa_cache.private_decrypt (::conf.rsa_key, p->challenge); 887 rsachallenge k;
886 888
887 if (!k) 889 if (0 > RSA_private_decrypt (sizeof (p->encr),
890 (unsigned char *)&p->encr, (unsigned char *)&k,
891 ::conf.rsa_key, RSA_PKCS1_OAEP_PADDING))
892 slog (L_ERR, _("challenge from %s (%s) illegal or corrupted"),
893 conf->nodename, (const char *)sockinfo (ssa));
894 else
888 { 895 {
889 slog (L_ERR, _("challenge from %s (%s) illegal or corrupted"), 896 retry_cnt = 0;
890 conf->nodename, (const char *)sockinfo (ssa)); 897 establish_connection.set (NOW + 8); //? ;)
898 keepalive.reset ();
899 rekey.reset ();
900
901 delete ictx;
902 ictx = 0;
903
904 delete octx;
905
906 octx = new crypto_ctx (k, 1);
907 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff;
908
909 send_auth_response (ssa, p->id, k);
910
891 break; 911 break;
892 } 912 }
913 }
893 914
894 retry_cnt = 0;
895 establish_connection.set (NOW + 8); //? ;)
896 keepalive.reset ();
897 rekey.reset ();
898 915
899 switch (p->subtype) 916 }
917
918 send_reset (ssa);
919 break;
920
921 case vpn_packet::PT_AUTH_RES:
922 {
923 auth_res_packet *p = (auth_res_packet *) pkt;
924
925 slog (L_TRACE, "<<%d PT_AUTH_RES", conf->id);
926
927 if (p->chk_config ())
928 {
929 if (p->prot_minor != PROTOCOL_MINOR)
930 slog (L_INFO, _("protocol minor version mismatch: ours is %d, %s's is %d."),
931 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
932
933 rsachallenge chg;
934
935 if (!rsa_cache.find (p->id, chg))
936 slog (L_ERR, _("unrequested auth response from %s (%s)"),
937 conf->nodename, (const char *)sockinfo (ssa));
938 else
900 { 939 {
901 case AUTH_INIT: 940 rsaresponse h;
902 case AUTH_INITREPLY:
903 delete ictx;
904 ictx = 0;
905 941
906 delete octx; 942 rsa_hash (chg, h);
907 943
908 octx = new crypto_ctx (*k, 1); 944 if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
909 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff;
910
911 send_auth (AUTH_REPLY, ssa, k);
912 break;
913
914 case AUTH_REPLY:
915
916 if (!memcmp ((u8 *)gen_challenge (seqrand, ssa), (u8 *)k, sizeof (rsachallenge)))
917 { 945 {
918 delete ictx; 946 delete ictx;
919 947
920 ictx = new crypto_ctx (*k, 0); 948 ictx = new crypto_ctx (chg, 0);
921 iseqno.reset (ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid 949 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
922 950
923 sa = *ssa; 951 sa = *ssa;
924 952
925 rekey.set (NOW + ::conf.rekey); 953 rekey.set (NOW + ::conf.rekey);
926 keepalive.set (NOW + ::conf.keepalive); 954 keepalive.set (NOW + ::conf.keepalive);
… …
936 964
937 slog (L_INFO, _("connection to %d (%s %s) established"), 965 slog (L_INFO, _("connection to %d (%s %s) established"),
938 conf->id, conf->nodename, (const char *)sockinfo (ssa)); 966 conf->id, conf->nodename, (const char *)sockinfo (ssa));
939 967
940 if (::conf.script_node_up) 968 if (::conf.script_node_up)
941 run_script (this, &connection::script_node_up, false); 969 run_script (run_script_cb (this, &connection::script_node_up), false);
970
971 break;
942 } 972 }
943 else 973 else
944 slog (L_ERR, _("sent and received challenge do not match with (%s %s))"), 974 slog (L_ERR, _("sent and received challenge do not match with (%s %s))"),
945 conf->nodename, (const char *)sockinfo (ssa)); 975 conf->nodename, (const char *)sockinfo (ssa));
946
947 break;
948 default:
949 slog (L_ERR, _("authentification illegal subtype error (%s %s)"),
950 conf->nodename, (const char *)sockinfo (ssa));
951 break;
952 } 976 }
953 } 977 }
954 else
955 send_reset (ssa);
956
957 break;
958 } 978 }
979
980 send_reset (ssa);
981 break;
959 982
960 case vpn_packet::PT_DATA_COMPRESSED: 983 case vpn_packet::PT_DATA_COMPRESSED:
961#if !ENABLE_COMPRESSION 984#if !ENABLE_COMPRESSION
962 send_reset (ssa); 985 send_reset (ssa);
963 break; 986 break;
964#endif 987#endif
988
965 case vpn_packet::PT_DATA_UNCOMPRESSED: 989 case vpn_packet::PT_DATA_UNCOMPRESSED:
966 990
967 if (ictx && octx) 991 if (ictx && octx)
968 { 992 {
969 vpndata_packet *p = (vpndata_packet *)pkt; 993 vpndata_packet *p = (vpndata_packet *)pkt;
… …
1062 connection *c = vpn->conns[p->id - 1]; 1086 connection *c = vpn->conns[p->id - 1];
1063 1087
1064 slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)", 1088 slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)",
1065 conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx); 1089 conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx);
1066 1090
1067 c->send_auth (AUTH_INIT, p->si.sa ()); 1091 c->send_auth_request (p->si.sa (), true);
1068 } 1092 }
1093
1069 break; 1094 break;
1070 1095
1071 default: 1096 default:
1072 send_reset (ssa); 1097 send_reset (ssa);
1073 break; 1098 break;
1099
1074 } 1100 }
1075} 1101}
1076 1102
1077void connection::keepalive_cb (tstamp &ts) 1103void connection::keepalive_cb (tstamp &ts)
1078{ 1104{
… …
1105 delete p; 1131 delete p;
1106} 1132}
1107 1133
1108void connection::script_node () 1134void connection::script_node ()
1109{ 1135{
1110 vpn->script_if_up (); 1136 vpn->script_if_up (0);
1111 1137
1112 char *env; 1138 char *env;
1113 asprintf (&env, "DESTID=%d", conf->id); 1139 asprintf (&env, "DESTID=%d", conf->id);
1114 putenv (env); 1140 putenv (env);
1115 asprintf (&env, "DESTNODE=%s", conf->nodename); 1141 asprintf (&env, "DESTNODE=%s", conf->nodename);
… …
1118 putenv (env); 1144 putenv (env);
1119 asprintf (&env, "DESTPORT=%d", ntohs (sa.sin_port)); 1145 asprintf (&env, "DESTPORT=%d", ntohs (sa.sin_port));
1120 putenv (env); 1146 putenv (env);
1121} 1147}
1122 1148
1123const char *connection::script_node_up () 1149const char *connection::script_node_up (int)
1124{ 1150{
1125 script_node (); 1151 script_node ();
1126 1152
1127 putenv ("STATE=up"); 1153 putenv ("STATE=up");
1128 1154
1129 return ::conf.script_node_up ? ::conf.script_node_up : "node-up"; 1155 return ::conf.script_node_up ? ::conf.script_node_up : "node-up";
1130} 1156}
1131 1157
1132const char *connection::script_node_down () 1158const char *connection::script_node_down (int)
1133{ 1159{
1134 script_node (); 1160 script_node ();
1135 1161
1136 putenv ("STATE=down"); 1162 putenv ("STATE=down");
1137 1163
… …
1156 shutdown (); 1182 shutdown ();
1157} 1183}
1158 1184
1159///////////////////////////////////////////////////////////////////////////// 1185/////////////////////////////////////////////////////////////////////////////
1160 1186
1161const char *vpn::script_if_up () 1187const char *vpn::script_if_up (int)
1162{ 1188{
1163 // the tunnel device mtu should be the physical mtu - overhead 1189 // the tunnel device mtu should be the physical mtu - overhead
1164 // the tricky part is rounding to the cipher key blocksize 1190 // the tricky part is rounding to the cipher key blocksize
1165 int mtu = conf.mtu - ETH_OVERHEAD - VPE_OVERHEAD - UDP_OVERHEAD; 1191 int mtu = conf.mtu - ETH_OVERHEAD - VPE_OVERHEAD - MAX_OVERHEAD;
1166 mtu += ETH_OVERHEAD - 6 - 6; // now we have the data portion 1192 mtu += ETH_OVERHEAD - 6 - 6; // now we have the data portion
1167 mtu -= mtu % EVP_CIPHER_block_size (CIPHER); // round 1193 mtu -= mtu % EVP_CIPHER_block_size (CIPHER); // round
1168 mtu -= ETH_OVERHEAD - 6 - 6; // and get interface mtu again 1194 mtu -= ETH_OVERHEAD - 6 - 6; // and get interface mtu again
1169 1195
1170 char *env; 1196 char *env;
… …
1224 { 1250 {
1225 slog (L_ERR, _("cannot create network interface '%s'"), conf.ifname); 1251 slog (L_ERR, _("cannot create network interface '%s'"), conf.ifname);
1226 exit (1); 1252 exit (1);
1227 } 1253 }
1228 1254
1229 run_script (this, &vpn::script_if_up, true); 1255 run_script (run_script_cb (this, &vpn::script_if_up), true);
1230 1256
1231 vpn_ev_watcher.start (tap->fd, POLLIN); 1257 vpn_ev_watcher.start (tap->fd, POLLIN);
1232 1258
1233 reconnect_all (); 1259 reconnect_all ();
1234 1260

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