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Comparing gvpe/src/connection.C (file contents):
Revision 1.70 by pcg, Thu Aug 7 19:07:02 2008 UTC vs.
Revision 1.110 by root, Thu Jan 9 08:15:05 2014 UTC

1/* 1/*
2 connection.C -- manage a single connection 2 connection.C -- manage a single connection
3 Copyright (C) 2003-2008 Marc Lehmann <gvpe@schmorp.de> 3 Copyright (C) 2003-2008,2010,2011,2013 Marc Lehmann <gvpe@schmorp.de>
4 4
5 This file is part of GVPE. 5 This file is part of GVPE.
6 6
7 GVPE is free software; you can redistribute it and/or modify it 7 GVPE is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the 8 under the terms of the GNU General Public License as published by the
… …
33 33
34#include <list> 34#include <list>
35#include <queue> 35#include <queue>
36#include <utility> 36#include <utility>
37 37
38#include <openssl/opensslv.h>
38#include <openssl/rand.h> 39#include <openssl/rand.h>
39#include <openssl/evp.h> 40#include <openssl/evp.h>
40#include <openssl/rsa.h> 41#include <openssl/rsa.h>
41#include <openssl/err.h> 42#include <openssl/err.h>
43
44// openssl 0.9.8 compatibility
45#if OPENSSL_VERSION_NUMBER < 0x10100000
46 #define require101(exp) exp
47#else
48 #define require101(exp) equire (exp)
49#endif
42 50
43#include "conf.h" 51#include "conf.h"
44#include "slog.h" 52#include "slog.h"
45#include "device.h" 53#include "device.h"
46#include "vpn.h" 54#include "vpn.h"
47#include "connection.h" 55#include "connection.h"
56#include "hkdf.h"
48 57
49#include "netcompat.h" 58#include "netcompat.h"
50 59
51#if !HAVE_RAND_PSEUDO_BYTES
52# define RAND_pseudo_bytes RAND_bytes
53#endif
54
55#define MAGIC "vped\xbd\xc6\xdb\x82" // 8 bytes of magic 60#define MAGIC "gvpe\xbd\xc6\xdb\x82" // 8 bytes of magic
61#define MAGIC "HUHN\xbd\xc6\xdb\x82" // 8 bytes of magic//D
56 62
57#define ULTRA_FAST 1 63#define ULTRA_FAST 1
58#define HLOG 15 64#define HLOG 15
59#include "lzf/lzf.h" 65#include "lzf/lzf.h"
60#include "lzf/lzf_c.c" 66#include "lzf/lzf_c.c"
… …
63////////////////////////////////////////////////////////////////////////////// 69//////////////////////////////////////////////////////////////////////////////
64 70
65static std::queue< std::pair<run_script_cb *, const char *> > rs_queue; 71static std::queue< std::pair<run_script_cb *, const char *> > rs_queue;
66static ev::child rs_child_ev; 72static ev::child rs_child_ev;
67 73
74namespace
75{
68void // c++ requires external linkage here, apparently :( 76 void // c++ requires external linkage here, apparently :(
69rs_child_cb (ev::child &w, int revents) 77 rs_child_cb (ev::child &w, int revents)
70{ 78 {
71 w.stop (); 79 w.stop ();
72 80
73 if (rs_queue.empty ()) 81 if (rs_queue.empty ())
74 return; 82 return;
75 83
76 pid_t pid = run_script (*rs_queue.front ().first, false); 84 pid_t pid = run_script (*rs_queue.front ().first, false);
77 if (pid) 85 if (pid)
78 { 86 {
79 w.set (pid); 87 w.set (pid);
80 w.start (); 88 w.start ();
81 } 89 }
82 else 90 else
83 slog (L_WARN, rs_queue.front ().second); 91 slog (L_WARN, rs_queue.front ().second);
84 92
85 delete rs_queue.front ().first; 93 delete rs_queue.front ().first;
86 rs_queue.pop (); 94 rs_queue.pop ();
87} 95 }
96};
88 97
89// despite the fancy name, this is quite a hack 98// despite the fancy name, this is quite a hack
90static void 99static void
91run_script_queued (run_script_cb *cb, const char *warnmsg) 100run_script_queued (run_script_cb *cb, const char *warnmsg)
92{ 101{
… …
104struct crypto_ctx 113struct crypto_ctx
105{ 114{
106 EVP_CIPHER_CTX cctx; 115 EVP_CIPHER_CTX cctx;
107 HMAC_CTX hctx; 116 HMAC_CTX hctx;
108 117
109 crypto_ctx (const rsachallenge &challenge, int enc); 118 crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc);
110 ~crypto_ctx (); 119 ~crypto_ctx ();
111}; 120};
112 121
113crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc) 122crypto_ctx::crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc)
114{ 123{
124 ecdh_key s;
125
126 curve25519_combine (a, b, s);
127
128 {
129 u8 mac_key[MAC_KEYSIZE];
130 static const unsigned char mac_info[] = "gvpe mac key";
131
132 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
133 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key));
134 kdf.extract (s, sizeof (s));
135 kdf.extract_done (HKDF_PRF_HASH ());
136 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info));
137
138 HMAC_CTX_init (&hctx);
139 require101 (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0));
140 }
141
142 {
143 u8 cipher_key[CIPHER_KEYSIZE];
144 static const unsigned char cipher_info[] = "gvpe cipher key";
145
146 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
147 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key));
148 kdf.extract (s, sizeof (s));
149 kdf.extract_done (HKDF_PRF_HASH ());
150 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info));
151
115 EVP_CIPHER_CTX_init (&cctx); 152 EVP_CIPHER_CTX_init (&cctx);
116 require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc)); 153 require (EVP_CipherInit_ex (&cctx, CIPHER (), 0, cipher_key, 0, enc));
117 HMAC_CTX_init (&hctx); 154 }
118 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
119} 155}
120 156
121crypto_ctx::~crypto_ctx () 157crypto_ctx::~crypto_ctx ()
122{ 158{
123 require (EVP_CIPHER_CTX_cleanup (&cctx)); 159 require (EVP_CIPHER_CTX_cleanup (&cctx));
124 HMAC_CTX_cleanup (&hctx); 160 HMAC_CTX_cleanup (&hctx);
125} 161}
126 162
163static inline void
164auth_encrypt (RSA *key, const auth_data &auth, auth_encr &encr)
165{
166 if (RSA_public_encrypt (sizeof (auth.rsa),
167 (unsigned char *)&auth.rsa, (unsigned char *)&encr.rsa,
168 key, RSA_PKCS1_OAEP_PADDING) < 0)
169 fatal ("RSA_public_encrypt error");
170
171 memcpy (&encr.ecdh, &auth.ecdh, sizeof (encr.ecdh));
172}
173
174static inline bool
175auth_decrypt (RSA *key, const auth_encr &encr, auth_data &auth)
176{
177 u8 rsa_decrypt[RSA_KEYLEN];
178
179 if (RSA_private_decrypt (sizeof (encr.rsa),
180 (const unsigned char *)&encr.rsa, (unsigned char *)rsa_decrypt,
181 key, RSA_PKCS1_OAEP_PADDING) != sizeof (auth.rsa))
182 return 0;
183
184 memcpy (&auth.rsa, rsa_decrypt, sizeof (auth.rsa));
185 memcpy (&auth.ecdh, &encr.ecdh, sizeof (auth.ecdh));
186
187 return 1;
188}
189
127static void 190static void
128rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) 191auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
129{ 192{
130 EVP_MD_CTX ctx; 193 hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt
131 194 kdf.extract (&auth.rsa, sizeof (auth.rsa));
132 EVP_MD_CTX_init (&ctx); 195 kdf.extract_done ();
133 require (EVP_DigestInit (&ctx, RSA_HASH)); 196 kdf.expand (mac, sizeof mac, auth.ecdh, sizeof (auth.ecdh)); // use challenge ecdh b as info
134 require (EVP_DigestUpdate(&ctx, &chg, sizeof chg));
135 require (EVP_DigestUpdate(&ctx, &id, sizeof id));
136 require (EVP_DigestFinal (&ctx, (unsigned char *)&h, 0));
137 EVP_MD_CTX_cleanup (&ctx);
138} 197}
139 198
140struct rsa_entry 199void
200connection::generate_auth_data ()
141{ 201{
142 tstamp expire; 202 if (auth_expire < ev_now ())
143 rsaid id;
144 rsachallenge chg;
145};
146
147struct rsa_cache : list<rsa_entry>
148{
149 inline void cleaner_cb (ev::timer &w, int revents); ev::timer cleaner;
150
151 bool find (const rsaid &id, rsachallenge &chg)
152 {
153 for (iterator i = begin (); i != end (); ++i)
154 { 203 {
155 if (!memcmp (&id, &i->id, sizeof id) && i->expire > ev_now ()) 204 // request data
156 { 205 rand_fill (snd_auth.rsa);
157 memcpy (&chg, &i->chg, sizeof chg); 206 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
158 207
159 erase (i); 208 // eventual response data
160 return true; 209 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
161 }
162 } 210 }
163 211
164 if (!cleaner.is_active ()) 212 // every use prolongs the expiry
165 cleaner.again ();
166
167 return false;
168 }
169
170 void gen (rsaid &id, rsachallenge &chg)
171 {
172 rsa_entry e;
173
174 RAND_bytes ((unsigned char *)&id, sizeof id);
175 RAND_bytes ((unsigned char *)&chg, sizeof chg);
176
177 e.expire = ev_now () + RSA_TTL; 213 auth_expire = ev_now () + AUTH_TTL;
178 e.id = id;
179 memcpy (&e.chg, &chg, sizeof chg);
180
181 push_back (e);
182
183 if (!cleaner.is_active ())
184 cleaner.again ();
185 }
186
187 rsa_cache ()
188 {
189 cleaner.set<rsa_cache, &rsa_cache::cleaner_cb> (this);
190 cleaner.set (RSA_TTL, RSA_TTL);
191 }
192
193} rsa_cache;
194
195void rsa_cache::cleaner_cb (ev::timer &w, int revents)
196{
197 if (empty ())
198 w.stop ();
199 else
200 {
201 for (iterator i = begin (); i != end (); )
202 if (i->expire <= ev_now ())
203 i = erase (i);
204 else
205 ++i;
206 }
207} 214}
208 215
209////////////////////////////////////////////////////////////////////////////// 216//////////////////////////////////////////////////////////////////////////////
210 217
211pkt_queue::pkt_queue (double max_ttl, int max_queue) 218pkt_queue::pkt_queue (double max_ttl, int max_queue)
… …
225 delete p; 232 delete p;
226 233
227 delete [] queue; 234 delete [] queue;
228} 235}
229 236
237void
230void pkt_queue::expire_cb (ev::timer &w, int revents) 238pkt_queue::expire_cb (ev::timer &w, int revents)
231{ 239{
232 ev_tstamp expire = ev_now () - max_ttl; 240 ev_tstamp expire = ev_now () - max_ttl;
233 241
234 for (;;) 242 for (;;)
235 { 243 {
… …
246 254
247 delete get (); 255 delete get ();
248 } 256 }
249} 257}
250 258
259void
251void pkt_queue::put (net_packet *p) 260pkt_queue::put (net_packet *p)
252{ 261{
253 ev_tstamp now = ev_now (); 262 ev_tstamp now = ev_now ();
254 263
255 // start expiry timer 264 // start expiry timer
256 if (empty ()) 265 if (empty ())
… …
265 queue[i].tstamp = now; 274 queue[i].tstamp = now;
266 275
267 i = ni; 276 i = ni;
268} 277}
269 278
270net_packet *pkt_queue::get () 279net_packet *
280pkt_queue::get ()
271{ 281{
272 if (empty ()) 282 if (empty ())
273 return 0; 283 return 0;
274 284
275 net_packet *p = queue[j].pkt; 285 net_packet *p = queue[j].pkt;
… …
299 309
300 bool can (const sockinfo &si) { return can((u32)si.host); } 310 bool can (const sockinfo &si) { return can((u32)si.host); }
301 bool can (u32 host); 311 bool can (u32 host);
302}; 312};
303 313
304net_rate_limiter auth_rate_limiter, reset_rate_limiter; 314static net_rate_limiter auth_rate_limiter, reset_rate_limiter;
305 315
316bool
306bool net_rate_limiter::can (u32 host) 317net_rate_limiter::can (u32 host)
307{ 318{
308 iterator i; 319 iterator i;
309 320
310 for (i = begin (); i != end (); ) 321 for (i = begin (); i != end (); )
311 if (i->host == host) 322 if (i->host == host)
… …
356 } 367 }
357} 368}
358 369
359///////////////////////////////////////////////////////////////////////////// 370/////////////////////////////////////////////////////////////////////////////
360 371
361unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE]; 372void
362
363void hmac_packet::hmac_gen (crypto_ctx *ctx) 373hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
364{ 374{
365 unsigned int xlen;
366
367 HMAC_CTX *hctx = &ctx->hctx; 375 HMAC_CTX *hctx = &ctx->hctx;
368 376
369 HMAC_Init_ex (hctx, 0, 0, 0, 0); 377 require101 (HMAC_Init_ex (hctx, 0, 0, 0, 0));
370 HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), 378 require101 (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet)));
371 len - sizeof (hmac_packet)); 379 require101 (HMAC_Final (hctx, hmac_digest, 0));
372 HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen);
373} 380}
374 381
375void 382void
376hmac_packet::hmac_set (crypto_ctx *ctx) 383hmac_packet::hmac_set (crypto_ctx *ctx)
377{ 384{
378 hmac_gen (ctx); 385 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
379 386 hmac_gen (ctx, hmac_digest);
380 memcpy (hmac, hmac_digest, HMACLENGTH); 387 memcpy (hmac, hmac_digest, HMACLENGTH);
381} 388}
382 389
383bool 390bool
384hmac_packet::hmac_chk (crypto_ctx *ctx) 391hmac_packet::hmac_chk (crypto_ctx *ctx)
385{ 392{
386 hmac_gen (ctx); 393 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
387 394 hmac_gen (ctx, hmac_digest);
388 return !memcmp (hmac, hmac_digest, HMACLENGTH); 395 return slow_memeq (hmac, hmac_digest, HMACLENGTH);
389} 396}
390 397
398void
391void vpn_packet::set_hdr (ptype type_, unsigned int dst) 399vpn_packet::set_hdr (ptype type_, unsigned int dst)
392{ 400{
393 type = type_; 401 type = type_;
394 402
395 int src = THISNODE->id; 403 int src = THISNODE->id;
396 404
… …
401 409
402#define MAXVPNDATA (MAX_MTU - 6 - 6) 410#define MAXVPNDATA (MAX_MTU - 6 - 6)
403#define DATAHDR (sizeof (u32) + RAND_SIZE) 411#define DATAHDR (sizeof (u32) + RAND_SIZE)
404 412
405struct vpndata_packet : vpn_packet 413struct vpndata_packet : vpn_packet
414{
415 u8 data[MAXVPNDATA + DATAHDR]; // seqno
416
417 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
418 tap_packet *unpack (connection *conn, u32 &seqno);
419
420private:
421 const u32 data_hdr_size () const
406 { 422 {
407 u8 data[MAXVPNDATA + DATAHDR]; // seqno
408
409 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
410 tap_packet *unpack (connection *conn, u32 &seqno);
411private:
412
413 const u32 data_hdr_size () const
414 {
415 return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR; 423 return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR;
416 }
417 }; 424 }
425};
418 426
419void 427void
420vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno) 428vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno)
421{ 429{
422 EVP_CIPHER_CTX *cctx = &conn->octx->cctx; 430 EVP_CIPHER_CTX *cctx = &conn->octx->cctx;
… …
424 ptype type = PT_DATA_UNCOMPRESSED; 432 ptype type = PT_DATA_UNCOMPRESSED;
425 433
426#if ENABLE_COMPRESSION 434#if ENABLE_COMPRESSION
427 u8 cdata[MAX_MTU]; 435 u8 cdata[MAX_MTU];
428 436
429 if (conn->features & ENABLE_COMPRESSION) 437 if (conn->features & FEATURE_COMPRESSION)
430 { 438 {
431 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7); 439 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7);
432 440
433 if (cl) 441 if (cl)
434 { 442 {
… …
440 d[1] = cl; 448 d[1] = cl;
441 } 449 }
442 } 450 }
443#endif 451#endif
444 452
445 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); 453 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 1));
446 454
447 struct { 455 struct {
448#if RAND_SIZE 456#if RAND_SIZE
449 u8 rnd[RAND_SIZE]; 457 u8 rnd[RAND_SIZE];
450#endif 458#endif
451 u32 seqno; 459 u32 seqno;
452 } datahdr; 460 } datahdr;
453 461
454 datahdr.seqno = ntohl (seqno); 462 datahdr.seqno = ntohl (seqno);
455#if RAND_SIZE 463#if RAND_SIZE
456 RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE); 464 // NB: a constant (per session) random prefix
465 // is likely enough, but we don't take any chances.
466 conn->oiv.get (datahdr.rnd, RAND_SIZE);
457#endif 467#endif
458 468
459 require (EVP_EncryptUpdate (cctx, 469 require (EVP_EncryptUpdate (cctx,
460 (unsigned char *) data + outl, &outl2, 470 (unsigned char *) data + outl, &outl2,
461 (unsigned char *) &datahdr, DATAHDR)); 471 (unsigned char *) &datahdr, DATAHDR));
… …
483 int outl = 0, outl2; 493 int outl = 0, outl2;
484 tap_packet *p = new tap_packet; 494 tap_packet *p = new tap_packet;
485 u8 *d; 495 u8 *d;
486 u32 l = len - data_hdr_size (); 496 u32 l = len - data_hdr_size ();
487 497
488 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); 498 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 0));
489 499
490#if ENABLE_COMPRESSION 500#if ENABLE_COMPRESSION
491 u8 cdata[MAX_MTU]; 501 u8 cdata[MAX_MTU];
492 502
493 if (type == PT_DATA_COMPRESSED) 503 if (type == PT_DATA_COMPRESSED)
494 d = cdata; 504 d = cdata;
495 else 505 else
496#endif 506#endif
497 d = &(*p)[6 + 6 - DATAHDR]; 507 d = &(*p)[6 + 6] - DATAHDR;
498 508
499 /* this overwrites part of the src mac, but we fix that later */ 509 // we play do evil games with the struct layout atm.
510 // pending better solutions, we at least do some verification.
511 // this is fine, as we left ISO territory long ago.
512 require (DATAHDR <= 16);
513 require ((u8 *)(&p->len + 1) == &(*p)[0]);
514
515 // this can overwrite the len/dst/src fields
500 require (EVP_DecryptUpdate (cctx, 516 require (EVP_DecryptUpdate (cctx,
501 d, &outl2, 517 d, &outl2,
502 (unsigned char *)&data, len - data_hdr_size ())); 518 (unsigned char *)&data, len - data_hdr_size ()));
503 outl += outl2; 519 outl += outl2;
504 520
… …
535 } 551 }
536}; 552};
537 553
538struct config_packet : vpn_packet 554struct config_packet : vpn_packet
539{ 555{
540 // actually, hmaclen cannot be checked because the hmac 556 u8 serial[SERIAL_SIZE];
541 // field comes before this data, so peers with other
542 // hmacs simply will not work.
543 u8 prot_major, prot_minor, randsize, hmaclen; 557 u8 prot_major, prot_minor, randsize;
544 u8 flags, challengelen, features, pad3; 558 u8 flags, features, pad6, pad7, pad8;
545 u32 cipher_nid, digest_nid, hmac_nid; 559 u32 cipher_nid, mac_nid, auth_nid;
546 560
547 void setup (ptype type, int dst); 561 void setup (ptype type, int dst);
548 bool chk_config () const; 562 bool chk_config (const conf_node *conf, const sockinfo &rsi) const;
549 563
550 static u8 get_features () 564 static u8 get_features ()
551 { 565 {
552 u8 f = 0; 566 u8 f = 0;
553#if ENABLE_COMPRESSION 567#if ENABLE_COMPRESSION
… …
561#endif 575#endif
562 return f; 576 return f;
563 } 577 }
564}; 578};
565 579
580void
566void config_packet::setup (ptype type, int dst) 581config_packet::setup (ptype type, int dst)
567{ 582{
568 prot_major = PROTOCOL_MAJOR; 583 prot_major = PROTOCOL_MAJOR;
569 prot_minor = PROTOCOL_MINOR; 584 prot_minor = PROTOCOL_MINOR;
570 randsize = RAND_SIZE; 585 randsize = RAND_SIZE;
571 hmaclen = HMACLENGTH;
572 flags = 0; 586 flags = 0;
573 challengelen = sizeof (rsachallenge);
574 features = get_features (); 587 features = get_features ();
575 588
589 strncpy ((char *)serial, conf.serial, sizeof (serial));
590
576 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 591 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
577 digest_nid = htonl (EVP_MD_type (RSA_HASH));
578 hmac_nid = htonl (EVP_MD_type (DIGEST)); 592 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ()));
593 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ()));
579 594
580 len = sizeof (*this) - sizeof (net_packet); 595 len = sizeof (*this) - sizeof (net_packet);
581 set_hdr (type, dst); 596 set_hdr (type, dst);
582} 597}
583 598
584bool config_packet::chk_config () const 599bool
600config_packet::chk_config (const conf_node *conf, const sockinfo &rsi) const
585{ 601{
586 if (prot_major != PROTOCOL_MAJOR) 602 if (prot_major != PROTOCOL_MAJOR)
587 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR); 603 slog (L_WARN, _("%s(%s): major version mismatch (remote %d <=> local %d)"),
604 conf->nodename, (const char *)rsi, prot_major, PROTOCOL_MAJOR);
588 else if (randsize != RAND_SIZE) 605 else if (randsize != RAND_SIZE)
589 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE); 606 slog (L_WARN, _("%s(%s): rand size mismatch (remote %d <=> local %d)"),
590 else if (hmaclen != HMACLENGTH) 607 conf->nodename, (const char *)rsi, randsize, RAND_SIZE);
591 slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH);
592 else if (challengelen != sizeof (rsachallenge))
593 slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge));
594 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER))) 608 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER ())))
595 slog (L_WARN, _("cipher mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER)); 609 slog (L_WARN, _("%s(%s): cipher algo mismatch (remote %x <=> local %x)"),
596 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH))) 610 conf->nodename, (const char *)rsi, ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER ()));
597 slog (L_WARN, _("digest mismatch (remote %x <=> local %x)"), ntohl (digest_nid), EVP_MD_type (RSA_HASH));
598 else if (hmac_nid != htonl (EVP_MD_type (DIGEST))) 611 else if (mac_nid != htonl (EVP_MD_type (MAC_DIGEST ())))
599 slog (L_WARN, _("hmac mismatch (remote %x <=> local %x)"), ntohl (hmac_nid), EVP_MD_type (DIGEST)); 612 slog (L_WARN, _("%s(%s): mac algo mismatch (remote %x <=> local %x)"),
613 conf->nodename, (const char *)rsi, ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ()));
614 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ())))
615 slog (L_WARN, _("%s(%s): auth algo mismatch (remote %x <=> local %x)"),
616 conf->nodename, (const char *)rsi, ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ()));
600 else 617 else
618 {
619 int cmp = memcmp (serial, ::conf.serial, sizeof (serial));
620
621 if (cmp > 0)
622 slog (L_WARN, _("%s(%s): remote serial newer than local serial - outdated config?"),
623 conf->nodename, (const char *)rsi);
624 else if (cmp == 0)
601 return true; 625 return true;
626 }
602 627
603 return false; 628 return false;
604} 629}
605 630
606struct auth_req_packet : config_packet 631struct auth_req_packet : config_packet // UNPROTECTED
607{ 632{
608 char magic[8]; 633 char magic[8];
609 u8 initiate; // false if this is just an automatic reply 634 u8 initiate; // false if this is just an automatic reply
610 u8 protocols; // supported protocols (will be patched on forward) 635 u8 protocols; // supported protocols (will be patched on forward)
611 u8 pad2, pad3; 636 u8 pad2, pad3;
612 rsaid id; 637 auth_encr encr;
613 rsaencrdata encr;
614 638
615 auth_req_packet (int dst, bool initiate_, u8 protocols_) 639 auth_req_packet (int dst, bool initiate_, u8 protocols_)
616 { 640 {
617 config_packet::setup (PT_AUTH_REQ, dst); 641 config_packet::setup (PT_AUTH_REQ, dst);
618 strncpy (magic, MAGIC, 8); 642 memcpy (magic, MAGIC, 8);
619 initiate = !!initiate_; 643 initiate = !!initiate_;
620 protocols = protocols_; 644 protocols = protocols_;
621 645
622 len = sizeof (*this) - sizeof (net_packet); 646 len = sizeof (*this) - sizeof (net_packet);
623 } 647 }
624}; 648};
625 649
626struct auth_res_packet : config_packet 650struct auth_res_packet : vpn_packet // UNPROTECTED
627{ 651{
628 rsaid id;
629 u8 pad1, pad2, pad3;
630 u8 response_len; // encrypted length
631 rsaresponse response; 652 auth_response response;
632 653
633 auth_res_packet (int dst) 654 auth_res_packet (int dst)
634 { 655 {
635 config_packet::setup (PT_AUTH_RES, dst); 656 set_hdr (PT_AUTH_RES, dst);
636 657
637 len = sizeof (*this) - sizeof (net_packet); 658 len = sizeof (*this) - sizeof (net_packet);
638 } 659 }
639}; 660};
640 661
… …
670}; 691};
671 692
672///////////////////////////////////////////////////////////////////////////// 693/////////////////////////////////////////////////////////////////////////////
673 694
674void 695void
675connection::connection_established () 696connection::connection_established (const sockinfo &rsi)
676{ 697{
677 slog (L_TRACE, _("%s: possible connection establish (ictx %d, octx %d)"), conf->nodename, !!ictx, !!octx); 698 if (!have_snd_auth || !have_rcv_auth)
699 return;
678 700
679 if (ictx && octx) 701 si = rsi;
702 protocol = rsi.prot;
703
704 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
705 conf->nodename, (const char *)rsi,
706 vpn->can_direct (THISNODE, conf) ? "direct" : "forwarded",
707 PROTOCOL_MAJOR, prot_minor);
708
709 if (::conf.script_node_up)
710 {
711 run_script_cb *cb = new run_script_cb;
712 cb->set<connection, &connection::script_node_up> (this);
713 run_script_queued (cb, _("node-up command execution failed, continuing."));
680 { 714 }
715
716 delete ictx; ictx = new crypto_ctx (rcv_auth, snd_auth, rcv_ecdh_a, rcv_auth.ecdh, 0);
717 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff);
718
719 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1);
720 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff;
721
722 oiv.reset ();
723
681 // make sure rekeying timeouts are slightly asymmetric 724 // make sure rekeying timeouts are slightly asymmetric
682 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0); 725 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
683 rekey.start (rekey_interval, rekey_interval); 726 rekey.start (rekey_interval, rekey_interval);
727
728 hmac_error = 0.;
729
684 keepalive.start (::conf.keepalive); 730 keepalive.start (::conf.keepalive);
685 731
686 // send queued packets 732 // send queued packets
687 if (ictx && octx)
688 {
689 while (tap_packet *p = (tap_packet *)data_queue.get ()) 733 while (tap_packet *p = (tap_packet *)data_queue.get ())
690 { 734 {
691 if (p->len) send_data_packet (p); 735 if (p->len) send_data_packet (p);
692 delete p; 736 delete p;
693 } 737 }
694 738
695 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) 739 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
696 { 740 {
697 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); 741 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
698 delete p; 742 delete p;
699 }
700 }
701 } 743 }
744
745 vpn->connection_established (this);
746}
747
748void
749connection::reset_si ()
750{
751 if (vpn->can_direct (THISNODE, conf))
752 protocol = best_protocol (THISNODE->protocols & conf->connectable_protocols ());
702 else 753 else
703 { 754 {
704 retry_cnt = 0;
705 establish_connection.start (5);
706 keepalive.stop ();
707 rekey.stop ();
708 }
709}
710
711void
712connection::reset_si ()
713{
714 protocol = best_protocol (THISNODE->protocols & conf->protocols);
715
716 // mask out protocols we cannot establish
717 if (!conf->udp_port) protocol &= ~PROT_UDPv4;
718 if (!conf->tcp_port) protocol &= ~PROT_TCPv4;
719 if (!conf->dns_port) protocol &= ~PROT_DNSv4;
720
721 if (protocol
722 && (!conf->can_direct (THISNODE)
723 || !THISNODE->can_direct (conf)))
724 {
725 slog (L_DEBUG, _("%s: direct connection denied"), conf->nodename); 755 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename);
726 protocol = 0; 756 protocol = 0;
727 } 757 }
728 758
729 si.set (conf, protocol); 759 si.set (conf, protocol);
730} 760}
… …
733const sockinfo & 763const sockinfo &
734connection::forward_si (const sockinfo &si) const 764connection::forward_si (const sockinfo &si) const
735{ 765{
736 if (!si.valid ()) 766 if (!si.valid ())
737 { 767 {
738 connection *r = vpn->find_router (); 768 connection *r = vpn->find_router_for (this);
739 769
740 if (r) 770 if (r)
741 { 771 {
742 slog (L_DEBUG, _("%s: no common protocol, trying indirectly through %s (%s)"), 772 slog (L_DEBUG, _("%s: no common protocol, trying to route through %s."),
743 conf->nodename, r->conf->nodename, (const char *)r->si); 773 conf->nodename, r->conf->nodename);
744 return r->si; 774 return r->si;
745 } 775 }
746 else 776 else
747 slog (L_DEBUG, _("%s: node unreachable, no common protocol"), 777 slog (L_DEBUG, _("%s: node unreachable, no common protocol or no router available."),
748 conf->nodename); 778 conf->nodename);
749 } 779 }
750 780
751 return si; 781 return si;
752} 782}
753 783
754void 784void
755connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) 785connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
756{ 786{
757 if (!vpn->send_vpn_packet (pkt, si, tos)) 787 if (!vpn->send_vpn_packet (pkt, si, tos))
758 reset_connection (); 788 reset_connection ("packet send error");
759} 789}
760 790
761void 791void
762connection::send_ping (const sockinfo &si, u8 pong) 792connection::send_ping (const sockinfo &si, u8 pong)
763{ 793{
764 ping_packet *pkt = new ping_packet; 794 ping_packet *pkt = new ping_packet;
765 795
766 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING); 796 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
797
798 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si);
767 send_vpn_packet (pkt, si, IPTOS_LOWDELAY); 799 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
768 800
769 delete pkt; 801 delete pkt;
770} 802}
771 803
… …
786void 818void
787connection::send_auth_request (const sockinfo &si, bool initiate) 819connection::send_auth_request (const sockinfo &si, bool initiate)
788{ 820{
789 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); 821 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
790 822
791 rsachallenge chg; 823 generate_auth_data ();
792 rsa_cache.gen (pkt->id, chg);
793 rsa_encrypt (conf->rsa_key, chg, pkt->encr); 824 auth_encrypt (conf->rsa_key, snd_auth, pkt->encr);
794 825
795 slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si); 826 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si);
796
797 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly 827 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
798 828
799 delete pkt; 829 delete pkt;
800} 830}
801 831
802void 832void
803connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 833connection::send_auth_response (const sockinfo &si)
804{ 834{
805 auth_res_packet *pkt = new auth_res_packet (conf->id); 835 auth_res_packet *pkt = new auth_res_packet (conf->id);
806 836
807 pkt->id = id; 837 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof rcv_ecdh_b);
838 auth_hash (rcv_auth, rcv_ecdh_b, pkt->response.mac);
808 839
809 rsa_hash (id, chg, pkt->response);
810
811 pkt->hmac_set (octx);
812
813 slog (L_TRACE, ">>%d PT_AUTH_RES [%s]", conf->id, (const char *)si); 840 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si);
814
815 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly 841 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly
816 842
817 delete pkt; 843 delete pkt;
818} 844}
819 845
820void 846void
821connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols) 847connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols)
822{ 848{
823 slog (L_TRACE, ">>%d PT_CONNECT_INFO(%d,%s)", 849 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s,p%02x)", conf->nodename,
824 conf->id, rid, (const char *)rsi); 850 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi,
851 conf->protocols);
825 852
826 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols); 853 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols);
827 854
828 r->hmac_set (octx); 855 r->hmac_set (octx);
829 send_vpn_packet (r, si); 856 send_vpn_packet (r, si);
… …
832} 859}
833 860
834inline void 861inline void
835connection::establish_connection_cb (ev::timer &w, int revents) 862connection::establish_connection_cb (ev::timer &w, int revents)
836{ 863{
837 if (!ictx 864 if (!(ictx && octx)
838 && conf != THISNODE 865 && conf != THISNODE
839 && connectmode != conf_node::C_NEVER 866 && connectmode != conf_node::C_NEVER
840 && connectmode != conf_node::C_DISABLED 867 && connectmode != conf_node::C_DISABLED
841 && !w.is_active ()) 868 && !w.is_active ())
842 { 869 {
843 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection 870 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection
844 // and stop trying. should probably be handled by a per-connection expire handler. 871 // and stop trying. should probably be handled by a per-connection expire handler.
845 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ()) 872 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ())
846 { 873 {
847 reset_connection (); 874 reset_connection ("no demand");
848 return; 875 return;
849 } 876 }
850 877
851 last_establish_attempt = ev_now (); 878 last_establish_attempt = ev_now ();
852 879
… …
854 ? (retry_cnt & 3) + 1 881 ? (retry_cnt & 3) + 1
855 : 1 << (retry_cnt >> 2)); 882 : 1 << (retry_cnt >> 2));
856 883
857 reset_si (); 884 reset_si ();
858 885
859 bool slow = si.prot & PROT_SLOW; 886 bool slow = (si.prot & PROT_SLOW) || (conf->low_power || THISNODE->low_power);
860 887
861 if (si.prot && !si.host) 888 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf))
862 { 889 {
863 slog (L_TRACE, _("%s: connection request (indirect)"), conf->nodename);
864 /*TODO*/ /* start the timer so we don't recurse endlessly */ 890 /*TODO*/ /* start the timer so we don't recurse endlessly */
865 w.start (1); 891 w.start (1);
866 vpn->send_connect_request (conf->id); 892 vpn->send_connect_request (this);
867 } 893 }
868 else 894 else
869 { 895 {
870 slog (L_TRACE, _("%s: connection request (direct)"), conf->nodename, !!ictx, !!octx); 896 if (si.valid ())
897 slog (L_DEBUG, _("%s: sending direct connection request to %s."),
898 conf->nodename, (const char *)si);
871 899
872 const sockinfo &dsi = forward_si (si); 900 const sockinfo &dsi = forward_si (si);
873 901
874 slow = slow || (dsi.prot & PROT_SLOW); 902 slow = slow || (dsi.prot & PROT_SLOW);
875 903
876 if (dsi.valid () && auth_rate_limiter.can (dsi)) 904 if (dsi.valid () && auth_rate_limiter.can (dsi))
877 { 905 {
878 if (retry_cnt < 4) 906 // use ping after the first few retries
907 // TODO: on rekeys, the other node might not interpret ping correctly,
908 // TODO: as it will still have a valid connection
909 if (retry_cnt < 4 && (!conf->low_power || THISNODE->low_power))
879 send_auth_request (dsi, true); 910 send_auth_request (dsi, true);
880 else 911 else
881 send_ping (dsi, 0); 912 send_ping (dsi, 0);
882 } 913 }
883 } 914 }
884 915
885 retry_int *= slow ? 8. : 0.9; 916 retry_int *= slow ? 4. : 0.9;
886 917
887 if (retry_int < conf->max_retry) 918 if (retry_int < conf->max_retry)
888 retry_cnt++; 919 retry_cnt++;
889 else 920 else
890 retry_int = conf->max_retry; 921 retry_int = conf->max_retry;
… …
892 w.start (retry_int); 923 w.start (retry_int);
893 } 924 }
894} 925}
895 926
896void 927void
897connection::reset_connection () 928connection::reset_connection (const char *reason)
898{ 929{
899 if (ictx && octx) 930 if (ictx && octx)
900 { 931 {
901 slog (L_INFO, _("%s(%s): connection lost"), 932 slog (L_INFO, _("%s(%s): connection lost (%s)"),
902 conf->nodename, (const char *)si); 933 conf->nodename, (const char *)si, reason);
903 934
904 if (::conf.script_node_down) 935 if (::conf.script_node_down)
905 { 936 {
906 run_script_cb *cb = new run_script_cb; 937 run_script_cb *cb = new run_script_cb;
907 cb->set<connection, &connection::script_node_down> (this); 938 cb->set<connection, &connection::script_node_down> (this);
… …
909 } 940 }
910 } 941 }
911 942
912 delete ictx; ictx = 0; 943 delete ictx; ictx = 0;
913 delete octx; octx = 0; 944 delete octx; octx = 0;
914#if ENABLE_DNS
915 dnsv4_reset_connection ();
916#endif
917 945
918 si.host = 0; 946 si.host = 0;
919 947
948 have_snd_auth = false;
949 have_rcv_auth = false;
950 auth_expire = 0.;
951
920 last_activity = 0; 952 last_activity = 0.;
953 //last_si_change = 0.;
921 retry_cnt = 0; 954 retry_cnt = 0;
922 955
923 rekey.stop (); 956 rekey.stop ();
924 keepalive.stop (); 957 keepalive.stop ();
925 establish_connection.stop (); 958 establish_connection.stop ();
… …
929connection::shutdown () 962connection::shutdown ()
930{ 963{
931 if (ictx && octx) 964 if (ictx && octx)
932 send_reset (si); 965 send_reset (si);
933 966
934 reset_connection (); 967 reset_connection ("shutdown");
935} 968}
936 969
970// poor-man's rekeying
937inline void 971inline void
938connection::rekey_cb (ev::timer &w, int revents) 972connection::rekey_cb (ev::timer &w, int revents)
939{ 973{
940 reset_connection (); 974 reset_connection ("rekeying");
941 establish_connection (); 975 establish_connection ();
942} 976}
943 977
944void 978void
945connection::send_data_packet (tap_packet *pkt) 979connection::send_data_packet (tap_packet *pkt)
… …
962 996
963void 997void
964connection::post_inject_queue () 998connection::post_inject_queue ()
965{ 999{
966 // force a connection every now and when when packets are sent (max 1/s) 1000 // force a connection every now and when when packets are sent (max 1/s)
967 if (ev_now () - last_establish_attempt >= 0.95) // arbitrary 1001 if (ev_now () - last_establish_attempt >= (conf->low_power || THISNODE->low_power ? 2.95 : 0.95)) // arbitrary
968 establish_connection.stop (); 1002 establish_connection.stop ();
969 1003
970 establish_connection (); 1004 establish_connection ();
971} 1005}
972 1006
… …
980 data_queue.put (new tap_packet (*pkt)); 1014 data_queue.put (new tap_packet (*pkt));
981 post_inject_queue (); 1015 post_inject_queue ();
982 } 1016 }
983} 1017}
984 1018
1019void
985void connection::inject_vpn_packet (vpn_packet *pkt, int tos) 1020connection::inject_vpn_packet (vpn_packet *pkt, int tos)
986{ 1021{
987 if (ictx && octx) 1022 if (ictx && octx)
988 send_vpn_packet (pkt, si, tos); 1023 send_vpn_packet (pkt, si, tos);
989 else 1024 else
990 { 1025 {
… …
996void 1031void
997connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) 1032connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
998{ 1033{
999 last_activity = ev_now (); 1034 last_activity = ev_now ();
1000 1035
1001 slog (L_NOISE, "<<%d received packet type %d from %d to %d", 1036 slog (L_NOISE, "%s >> received packet type %d from %d to %d.",
1002 conf->id, pkt->typ (), pkt->src (), pkt->dst ()); 1037 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ());
1003 1038
1004 if (connectmode == conf_node::C_DISABLED) 1039 if (connectmode == conf_node::C_DISABLED)
1005 return; 1040 return;
1006 1041
1007 switch (pkt->typ ()) 1042 switch (pkt->typ ())
1008 { 1043 {
1009 case vpn_packet::PT_PING: 1044 case vpn_packet::PT_PING:
1045 slog (L_TRACE, "%s >> PT_PING", conf->nodename);
1046
1010 // we send pings instead of auth packets after some retries, 1047 // we send pings instead of auth packets after some retries,
1011 // so reset the retry counter and establish a connection 1048 // so reset the retry counter and establish a connection
1012 // when we receive a ping. 1049 // when we receive a ping.
1013 if (!ictx) 1050 if (!ictx)
1014 { 1051 {
1015 if (auth_rate_limiter.can (rsi)) 1052 if (auth_rate_limiter.can (rsi))
1016 send_auth_request (rsi, true); 1053 send_auth_request (rsi, true);
1017 } 1054 }
1018 else 1055 else
1056 // we would love to change the socket address here, but ping's aren't
1057 // authenticated, so we best ignore it.
1019 send_ping (rsi, 1); // pong 1058 send_ping (rsi, 1); // pong
1020 1059
1021 break; 1060 break;
1022 1061
1023 case vpn_packet::PT_PONG: 1062 case vpn_packet::PT_PONG:
1063 slog (L_TRACE, "%s >> PT_PONG", conf->nodename);
1064
1065 // a PONG might mean that the other side doesn't really know
1066 // about our desire for communication.
1067 establish_connection ();
1024 break; 1068 break;
1025 1069
1026 case vpn_packet::PT_RESET: 1070 case vpn_packet::PT_RESET:
1071 slog (L_TRACE, "%s >> PT_RESET", conf->nodename);
1072
1073 if (ictx && octx)
1027 { 1074 {
1028 reset_connection (); 1075 reset_connection ("remote reset");
1029 1076
1030 config_packet *p = (config_packet *) pkt; 1077 config_packet *p = (config_packet *) pkt;
1031 1078
1032 if (!p->chk_config ()) 1079 if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
1033 {
1034 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node"),
1035 conf->nodename, (const char *)rsi);
1036 connectmode = conf_node::C_DISABLED;
1037 }
1038 else if (connectmode == conf_node::C_ALWAYS)
1039 establish_connection (); 1080 establish_connection ();
1040 } 1081 }
1082
1041 break; 1083 break;
1042 1084
1043 case vpn_packet::PT_AUTH_REQ: 1085 case vpn_packet::PT_AUTH_REQ:
1044 if (auth_rate_limiter.can (rsi)) 1086 if (auth_rate_limiter.can (rsi))
1045 { 1087 {
1046 auth_req_packet *p = (auth_req_packet *) pkt; 1088 auth_req_packet *p = (auth_req_packet *)pkt;
1047 1089
1048 slog (L_TRACE, "<<%d PT_AUTH_REQ(%d)", conf->id, p->initiate); 1090 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)",
1091 conf->nodename, p->initiate ? "initiate" : "reply",
1092 p->protocols, p->features);
1049 1093
1050 if (p->chk_config () && !strncmp (p->magic, MAGIC, 8)) 1094 if (memcmp (p->magic, MAGIC, 8))
1095 {
1096 slog (L_WARN, _("%s(%s): protocol magic mismatch - stray packet?"),
1097 conf->nodename, (const char *)rsi);
1098 }
1099 else if (p->chk_config (conf, rsi))
1051 { 1100 {
1052 if (p->prot_minor != PROTOCOL_MINOR) 1101 if (p->prot_minor != PROTOCOL_MINOR)
1053 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), 1102 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1054 conf->nodename, (const char *)rsi, 1103 conf->nodename, (const char *)rsi,
1055 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1104 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1056 1105
1057 if (p->initiate) 1106 if (p->initiate)
1107 {
1058 send_auth_request (rsi, false); 1108 send_auth_request (rsi, false);
1059 1109
1060 rsachallenge k; 1110 if (ictx && octx)
1111 reset_connection ("reconnect");
1112 }
1061 1113
1114 auth_data auth;
1115
1062 if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) 1116 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
1063 { 1117 {
1064 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), 1118 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
1065 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0)); 1119 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
1066 break;
1067 } 1120 }
1068 else 1121 else
1069 { 1122 {
1070 delete octx; 1123 bool chg = !have_rcv_auth || !slow_memeq (&rcv_auth, &auth, sizeof auth);
1071 1124
1072 octx = new crypto_ctx (k, 1); 1125 rcv_auth = auth;
1073 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 1126 have_rcv_auth = true;
1074 1127
1128 send_auth_response (rsi);
1129
1130 if (chg)
1131 {
1075 conf->protocols = p->protocols; 1132 conf->protocols = p->protocols;
1076 features = p->features & config_packet::get_features (); 1133 features = p->features & config_packet::get_features ();
1077 1134
1078 send_auth_response (rsi, p->id, k);
1079
1080 connection_established (); 1135 connection_established (rsi);
1081
1082 break; 1136 }
1083 } 1137 }
1138
1139 break;
1084 } 1140 }
1085 else
1086 slog (L_WARN, _("%s(%s): protocol mismatch"),
1087 conf->nodename, (const char *)rsi);
1088 1141
1089 send_reset (rsi); 1142 send_reset (rsi);
1090 } 1143 }
1091 1144
1092 break; 1145 break;
1093 1146
1094 case vpn_packet::PT_AUTH_RES: 1147 case vpn_packet::PT_AUTH_RES:
1095 { 1148 {
1096 auth_res_packet *p = (auth_res_packet *) pkt; 1149 auth_res_packet *p = (auth_res_packet *)pkt;
1097 1150
1098 slog (L_TRACE, "<<%d PT_AUTH_RES", conf->id); 1151 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
1099 1152
1100 if (p->chk_config ()) 1153 auth_mac local_mac;
1154 auth_hash (snd_auth, p->response.ecdh, local_mac);
1155
1156 if (!slow_memeq (&p->response.mac, local_mac, sizeof local_mac))
1101 { 1157 {
1102 if (p->prot_minor != PROTOCOL_MINOR)
1103 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1104 conf->nodename, (const char *)rsi,
1105 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1106
1107 rsachallenge chg;
1108
1109 if (!rsa_cache.find (p->id, chg))
1110 {
1111 slog (L_ERR, _("%s(%s): unrequested auth response ignored"), 1158 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
1112 conf->nodename, (const char *)rsi); 1159 conf->nodename, (const char *)rsi);
1113 break;
1114 } 1160 }
1115 else 1161 else if (!have_snd_auth)
1116 { 1162 {
1117 crypto_ctx *cctx = new crypto_ctx (chg, 0); 1163 memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
1118 1164
1119 if (!p->hmac_chk (cctx)) 1165 have_snd_auth = true;
1120 {
1121 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
1122 "could be an attack, or just corruption or a synchronization error"),
1123 conf->nodename, (const char *)rsi);
1124 break;
1125 }
1126 else
1127 {
1128 rsaresponse h;
1129
1130 rsa_hash (p->id, chg, h);
1131
1132 if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
1133 {
1134 prot_minor = p->prot_minor;
1135
1136 delete ictx; ictx = cctx;
1137
1138 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
1139
1140 si = rsi;
1141 protocol = rsi.prot;
1142
1143 connection_established (); 1166 connection_established (rsi);
1144
1145 slog (L_INFO, _("%s(%s): connection established, protocol version %d.%d"),
1146 conf->nodename, (const char *)rsi,
1147 p->prot_major, p->prot_minor);
1148
1149 if (::conf.script_node_up)
1150 {
1151 run_script_cb *cb = new run_script_cb;
1152 cb->set<connection, &connection::script_node_up> (this);
1153 run_script_queued (cb, _("node-up command execution failed, continuing."));
1154 }
1155
1156 break;
1157 }
1158 else
1159 slog (L_ERR, _("%s(%s): sent and received challenge do not match"),
1160 conf->nodename, (const char *)rsi);
1161 }
1162
1163 delete cctx;
1164 }
1165 } 1167 }
1166 } 1168 }
1167
1168 send_reset (rsi);
1169 break; 1169 break;
1170 1170
1171 case vpn_packet::PT_DATA_COMPRESSED: 1171 case vpn_packet::PT_DATA_COMPRESSED:
1172#if !ENABLE_COMPRESSION 1172#if !ENABLE_COMPRESSION
1173 send_reset (rsi); 1173 send_reset (rsi);
… …
1179 if (ictx && octx) 1179 if (ictx && octx)
1180 { 1180 {
1181 vpndata_packet *p = (vpndata_packet *)pkt; 1181 vpndata_packet *p = (vpndata_packet *)pkt;
1182 1182
1183 if (!p->hmac_chk (ictx)) 1183 if (!p->hmac_chk (ictx))
1184 {
1185 // rekeying often creates temporary hmac auth floods
1186 // we assume they don't take longer than a few seconds normally,
1187 // and suppress messages and resets during that time.
1188 //TODO: should be done per source address
1189 if (!hmac_error)
1190 {
1191 hmac_error = ev_now () + 3;
1192 break;
1193 }
1194 else if (hmac_error >= ev_now ())
1195 break; // silently suppress
1196 else
1197 {
1184 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" 1198 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
1185 "could be an attack, or just corruption or a synchronization error"), 1199 "could be an attack, or just corruption or a synchronization error."),
1186 conf->nodename, (const char *)rsi); 1200 conf->nodename, (const char *)rsi);
1201 // reset
1202 }
1203 }
1187 else 1204 else
1188 { 1205 {
1189 u32 seqno; 1206 u32 seqno;
1190 tap_packet *d = p->unpack (this, seqno); 1207 tap_packet *d = p->unpack (this, seqno);
1208 int seqclass = iseqno.seqno_classify (seqno);
1191 1209
1192 if (iseqno.recv_ok (seqno)) 1210 hmac_error = 0;
1211
1212 if (seqclass == 0) // ok
1193 { 1213 {
1194 vpn->tap->send (d); 1214 vpn->tap->send (d);
1195 1215
1196 if (si != rsi) 1216 if (si != rsi)
1197 { 1217 {
1198 // fast re-sync on source address changes, useful especially for tcp/ip 1218 // fast re-sync on source address changes, useful especially for tcp/ip
1219 //if (last_si_change < ev_now () + 5.)
1199 si = rsi; 1220 // {
1200
1201 slog (L_INFO, _("%s(%s): socket address changed to %s"), 1221 slog (L_INFO, _("%s(%s): changing socket address to %s."),
1202 conf->nodename, (const char *)si, (const char *)rsi); 1222 conf->nodename, (const char *)si, (const char *)rsi);
1223
1224 si = rsi;
1225
1226 if (::conf.script_node_change)
1227 {
1228 run_script_cb *cb = new run_script_cb;
1229 cb->set<connection, &connection::script_node_change> (this);
1230 run_script_queued (cb, _("node-change command execution failed, continuing."));
1231 }
1232
1233 // }
1234 //else
1235 // slog (L_INFO, _("%s(%s): accepted packet from %s, not (yet) redirecting traffic."),
1236 // conf->nodename, (const char *)si, (const char *)rsi);
1203 } 1237 }
1238 }
1239 else if (seqclass == 1) // far history
1240 slog (L_ERR, _("received very old packet (received %08lx, expected %08lx). "
1241 "possible replay attack, or just packet duplication/delay, ignoring."), seqno, iseqno.seq + 1);
1242 else if (seqclass == 2) // in-window duplicate, happens often on wireless
1243 slog (L_DEBUG, _("received recent duplicated packet (received %08lx, expected %08lx). "
1244 "possible replay attack, or just packet duplication, ignoring."), seqno, iseqno.seq + 1);
1245 else if (seqclass == 3) // reset
1246 {
1247 slog (L_ERR, _("received out-of-sync (far future) packet (received %08lx, expected %08lx). "
1248 "probably just massive packet loss, sending reset."), seqno, iseqno.seq + 1);
1249 send_reset (rsi);
1204 } 1250 }
1205 1251
1206 delete d; 1252 delete d;
1207 break; 1253 break;
1208 } 1254 }
… …
1212 break; 1258 break;
1213 1259
1214 case vpn_packet::PT_CONNECT_REQ: 1260 case vpn_packet::PT_CONNECT_REQ:
1215 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) 1261 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
1216 { 1262 {
1217 connect_req_packet *p = (connect_req_packet *) pkt; 1263 connect_req_packet *p = (connect_req_packet *)pkt;
1218 1264
1219 if (p->id > 0 && p->id <= vpn->conns.size ()) 1265 if (p->id > 0 && p->id <= vpn->conns.size ())
1220 { 1266 {
1221 connection *c = vpn->conns[p->id - 1]; 1267 connection *c = vpn->conns[p->id - 1];
1222 conf->protocols = p->protocols; 1268 conf->protocols = p->protocols;
1223 1269
1224 slog (L_TRACE, "<<%d PT_CONNECT_REQ(%d) [%d]", 1270 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s,p%02x) [%d]",
1271 conf->nodename, vpn->conns[p->id - 1]->conf->nodename,
1272 p->protocols,
1225 conf->id, p->id, c->ictx && c->octx); 1273 c->ictx && c->octx);
1226 1274
1227 if (c->ictx && c->octx) 1275 if (c->ictx && c->octx)
1228 { 1276 {
1229 // send connect_info packets to both sides, in case one is 1277 // send connect_info packets to both sides, in case one is
1230 // behind a nat firewall (or both ;) 1278 // behind a nat firewall (or both ;)
… …
1253 1301
1254 c->conf->protocols = p->protocols; 1302 c->conf->protocols = p->protocols;
1255 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf)); 1303 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf));
1256 p->si.upgrade_protocol (protocol, c->conf); 1304 p->si.upgrade_protocol (protocol, c->conf);
1257 1305
1258 slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)", 1306 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s,protocols=%02x,protocol=%02x,upgradable=%02x) [%d]",
1259 conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx); 1307 conf->nodename,
1308 vpn->conns[p->id - 1]->conf->nodename,
1309 (const char *)p->si,
1310 p->protocols,
1311 protocol,
1312 p->si.supported_protocols (c->conf),
1313 !c->ictx && !c->octx);
1260 1314
1261 const sockinfo &dsi = forward_si (p->si); 1315 const sockinfo &dsi = forward_si (p->si);
1262 1316
1263 if (dsi.valid ()) 1317 if (dsi.valid ())
1264 c->send_auth_request (dsi, true); 1318 c->send_auth_request (dsi, true);
1319 else
1320 slog (L_INFO, "connect info for %s received (%s), but still unable to contact.",
1321 vpn->conns[p->id - 1]->conf->nodename,
1322 (const char *)p->si);
1265 } 1323 }
1266 else 1324 else
1267 slog (L_WARN, 1325 slog (L_WARN,
1268 _("received authenticated connection request from unknown node #%d, config file mismatch?"), 1326 _("received authenticated connection request from unknown node #%d, config file mismatch?"),
1269 p->id); 1327 p->id);
… …
1278} 1336}
1279 1337
1280inline void 1338inline void
1281connection::keepalive_cb (ev::timer &w, int revents) 1339connection::keepalive_cb (ev::timer &w, int revents)
1282{ 1340{
1283 if (ev_now () >= last_activity + ::conf.keepalive + 30) 1341 ev_tstamp when = last_activity + ::conf.keepalive - ev::now ();
1342
1343 if (when >= 0)
1344 w.start (when);
1345 else if (when < -15)
1284 { 1346 {
1285 reset_connection (); 1347 reset_connection ("keepalive overdue");
1286 establish_connection (); 1348 establish_connection ();
1287 } 1349 }
1288 else if (ev_now () < last_activity + ::conf.keepalive)
1289 w.start (last_activity + ::conf.keepalive - ev::now ());
1290 else if (conf->connectmode != conf_node::C_ONDEMAND 1350 else if (conf->connectmode != conf_node::C_ONDEMAND
1291 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1351 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1292 { 1352 {
1353 w.start (3);
1293 send_ping (si); 1354 send_ping (si);
1294 w.start (5);
1295 } 1355 }
1296 else if (ev_now () < last_activity + ::conf.keepalive + 10) 1356 else if (when >= -10)
1297 // hold ondemand connections implicitly a few seconds longer 1357 // hold ondemand connections implicitly a few seconds longer
1298 // should delete octx, though, or something like that ;) 1358 // should delete octx, though, or something like that ;)
1299 w.start (last_activity + ::conf.keepalive + 10 - ev::now ()); 1359 w.start (when + 10);
1300 else 1360 else
1301 reset_connection (); 1361 reset_connection ("keepalive timeout");
1302} 1362}
1303 1363
1364void
1304void connection::send_connect_request (int id) 1365connection::send_connect_request (int id)
1305{ 1366{
1306 connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols); 1367 connect_req_packet *p = new connect_req_packet (conf->id, id, THISNODE->protocols);
1307 1368
1308 slog (L_TRACE, ">>%d PT_CONNECT_REQ(%d)", conf->id, id); 1369 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s,p%02x)",
1370 conf->nodename, vpn->conns[id - 1]->conf->nodename,
1371 THISNODE->protocols);
1309 p->hmac_set (octx); 1372 p->hmac_set (octx);
1310 send_vpn_packet (p, si); 1373 send_vpn_packet (p, si);
1311 1374
1312 delete p; 1375 delete p;
1313} 1376}
1314 1377
1378void
1315void connection::script_init_env (const char *ext) 1379connection::script_init_env (const char *ext)
1316{ 1380{
1317 char *env; 1381 char *env;
1318 asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env); 1382 asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env);
1319 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env); 1383 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env);
1320 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext, 1384 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext,
1321 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8, 1385 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8,
1322 conf->id & 0xff); putenv (env); 1386 conf->id & 0xff); putenv (env);
1323} 1387}
1324 1388
1389void
1325void connection::script_init_connect_env () 1390connection::script_init_connect_env ()
1326{ 1391{
1327 vpn->script_init_env (); 1392 vpn->script_init_env ();
1328 1393
1329 char *env; 1394 char *env;
1330 asprintf (&env, "DESTID=%d", conf->id); putenv (env); 1395 asprintf (&env, "DESTID=%d", conf->id); putenv (env);
1396 asprintf (&env, "DESTSI=%s", (const char *)si); putenv (env);
1331 asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env); 1397 asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env);
1332 asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env); 1398 asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env);
1333 asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env); 1399 asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env);
1334} 1400}
1335 1401
1336inline const char * 1402inline const char *
1337connection::script_node_up () 1403connection::script_node_up ()
1338{ 1404{
… …
1348 1414
1349 return filename; 1415 return filename;
1350} 1416}
1351 1417
1352inline const char * 1418inline const char *
1419connection::script_node_change ()
1420{
1421 script_init_connect_env ();
1422
1423 putenv ((char *)"STATE=change");
1424
1425 char *filename;
1426 asprintf (&filename,
1427 "%s/%s",
1428 confbase,
1429 ::conf.script_node_change ? ::conf.script_node_change : "node-change");
1430
1431 return filename;
1432}
1433
1434inline const char *
1353connection::script_node_down () 1435connection::script_node_down ()
1354{ 1436{
1355 script_init_connect_env (); 1437 script_init_connect_env ();
1356 1438
1357 putenv ((char *)"STATE=down"); 1439 putenv ((char *)"STATE=down");
… …
1368connection::connection (struct vpn *vpn, conf_node *conf) 1450connection::connection (struct vpn *vpn, conf_node *conf)
1369: vpn(vpn), conf(conf), 1451: vpn(vpn), conf(conf),
1370#if ENABLE_DNS 1452#if ENABLE_DNS
1371 dns (0), 1453 dns (0),
1372#endif 1454#endif
1373 data_queue(conf->max_ttl, conf->max_queue), 1455 data_queue(conf->max_ttl, conf->max_queue + 1),
1374 vpn_queue(conf->max_ttl, conf->max_queue) 1456 vpn_queue(conf->max_ttl, conf->max_queue + 1)
1375{ 1457{
1376 rekey .set<connection, &connection::rekey_cb > (this); 1458 rekey .set<connection, &connection::rekey_cb > (this);
1377 keepalive .set<connection, &connection::keepalive_cb > (this); 1459 keepalive .set<connection, &connection::keepalive_cb > (this);
1378 establish_connection.set<connection, &connection::establish_connection_cb> (this); 1460 establish_connection.set<connection, &connection::establish_connection_cb> (this);
1379 1461
1380 last_establish_attempt = 0.; 1462 last_establish_attempt = 0.;
1381 octx = ictx = 0; 1463 octx = ictx = 0;
1382 1464
1383 if (!conf->protocols) // make sure some protocol is enabled
1384 conf->protocols = PROT_UDPv4;
1385
1386 connectmode = conf->connectmode; 1465 connectmode = conf->connectmode;
1387 1466
1388 // queue a dummy packet to force an initial connection attempt 1467 // queue a dummy packet to force an initial connection attempt
1389 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) 1468 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
1390 vpn_queue.put (new net_packet); 1469 vpn_queue.put (new net_packet);
1391 1470
1392 reset_connection (); 1471 reset_connection ("startup");
1393} 1472}
1394 1473
1395connection::~connection () 1474connection::~connection ()
1396{ 1475{
1397 shutdown (); 1476 shutdown ();
1398} 1477}
1399 1478
1479void
1400void connection_init () 1480connection_init ()
1401{ 1481{
1402 auth_rate_limiter.clear (); 1482 auth_rate_limiter.clear ();
1403 reset_rate_limiter.clear (); 1483 reset_rate_limiter.clear ();
1404} 1484}
1405 1485

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