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Comparing gvpe/src/connection.C (file contents):
Revision 1.74 by pcg, Sun Aug 10 02:49:21 2008 UTC vs.
Revision 1.112 by root, Fri Sep 12 10:40:43 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) require (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
56 61
57#define ULTRA_FAST 1 62#define ULTRA_FAST 1
58#define HLOG 15 63#define HLOG 15
59#include "lzf/lzf.h" 64#include "lzf/lzf.h"
60#include "lzf/lzf_c.c" 65#include "lzf/lzf_c.c"
… …
63////////////////////////////////////////////////////////////////////////////// 68//////////////////////////////////////////////////////////////////////////////
64 69
65static std::queue< std::pair<run_script_cb *, const char *> > rs_queue; 70static std::queue< std::pair<run_script_cb *, const char *> > rs_queue;
66static ev::child rs_child_ev; 71static ev::child rs_child_ev;
67 72
73namespace
74{
68void // c++ requires external linkage here, apparently :( 75 void // c++ requires external linkage here, apparently :(
69rs_child_cb (ev::child &w, int revents) 76 rs_child_cb (ev::child &w, int revents)
70{ 77 {
71 w.stop (); 78 w.stop ();
72 79
73 if (rs_queue.empty ()) 80 if (rs_queue.empty ())
74 return; 81 return;
75 82
76 pid_t pid = run_script (*rs_queue.front ().first, false); 83 pid_t pid = run_script (*rs_queue.front ().first, false);
77 if (pid) 84 if (pid)
78 { 85 {
79 w.set (pid); 86 w.set (pid);
80 w.start (); 87 w.start ();
81 } 88 }
82 else 89 else
83 slog (L_WARN, rs_queue.front ().second); 90 slog (L_WARN, rs_queue.front ().second);
84 91
85 delete rs_queue.front ().first; 92 delete rs_queue.front ().first;
86 rs_queue.pop (); 93 rs_queue.pop ();
87} 94 }
95};
88 96
89// despite the fancy name, this is quite a hack 97// despite the fancy name, this is quite a hack
90static void 98static void
91run_script_queued (run_script_cb *cb, const char *warnmsg) 99run_script_queued (run_script_cb *cb, const char *warnmsg)
92{ 100{
… …
104struct crypto_ctx 112struct crypto_ctx
105{ 113{
106 EVP_CIPHER_CTX cctx; 114 EVP_CIPHER_CTX cctx;
107 HMAC_CTX hctx; 115 HMAC_CTX hctx;
108 116
109 crypto_ctx (const rsachallenge &challenge, int enc); 117 crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc);
110 ~crypto_ctx (); 118 ~crypto_ctx ();
111}; 119};
112 120
113crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc) 121crypto_ctx::crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc)
114{ 122{
123 ecdh_key s;
124
125 curve25519_combine (a, b, s);
126
127 {
128 u8 mac_key[MAC_KEYSIZE];
129 static const unsigned char mac_info[] = "gvpe mac key";
130
131 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
132 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key));
133 kdf.extract (s, sizeof (s));
134 kdf.extract_done (HKDF_PRF_HASH ());
135 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info));
136
137 HMAC_CTX_init (&hctx);
138 require101 (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0));
139 }
140
141 {
142 u8 cipher_key[CIPHER_KEYSIZE];
143 static const unsigned char cipher_info[] = "gvpe cipher key";
144
145 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
146 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key));
147 kdf.extract (s, sizeof (s));
148 kdf.extract_done (HKDF_PRF_HASH ());
149 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info));
150
115 EVP_CIPHER_CTX_init (&cctx); 151 EVP_CIPHER_CTX_init (&cctx);
116 require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc)); 152 require (EVP_CipherInit_ex (&cctx, CIPHER (), 0, cipher_key, 0, enc));
117 HMAC_CTX_init (&hctx); 153 }
118 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
119} 154}
120 155
121crypto_ctx::~crypto_ctx () 156crypto_ctx::~crypto_ctx ()
122{ 157{
123 require (EVP_CIPHER_CTX_cleanup (&cctx)); 158 require (EVP_CIPHER_CTX_cleanup (&cctx));
124 HMAC_CTX_cleanup (&hctx); 159 HMAC_CTX_cleanup (&hctx);
125} 160}
126 161
162static inline void
163auth_encrypt (RSA *key, const auth_data &auth, auth_encr &encr)
164{
165 if (RSA_public_encrypt (sizeof (auth.rsa),
166 (unsigned char *)&auth.rsa, (unsigned char *)&encr.rsa,
167 key, RSA_PKCS1_OAEP_PADDING) < 0)
168 fatal ("RSA_public_encrypt error");
169
170 memcpy (&encr.ecdh, &auth.ecdh, sizeof (encr.ecdh));
171}
172
173static inline bool
174auth_decrypt (RSA *key, const auth_encr &encr, auth_data &auth)
175{
176 u8 rsa_decrypt[RSA_KEYLEN];
177
178 if (RSA_private_decrypt (sizeof (encr.rsa),
179 (const unsigned char *)&encr.rsa, (unsigned char *)rsa_decrypt,
180 key, RSA_PKCS1_OAEP_PADDING) != sizeof (auth.rsa))
181 return 0;
182
183 memcpy (&auth.rsa, rsa_decrypt, sizeof (auth.rsa));
184 memcpy (&auth.ecdh, &encr.ecdh, sizeof (auth.ecdh));
185
186 return 1;
187}
188
127static void 189static void
128rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) 190auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
129{ 191{
130 EVP_MD_CTX ctx; 192 hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt
131 193 kdf.extract (&auth.rsa, sizeof (auth.rsa));
132 EVP_MD_CTX_init (&ctx); 194 kdf.extract_done ();
133 require (EVP_DigestInit (&ctx, RSA_HASH)); 195 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} 196}
139 197
140struct rsa_entry 198void
199connection::generate_auth_data ()
141{ 200{
142 tstamp expire; 201 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 { 202 {
155 if (!memcmp (&id, &i->id, sizeof id) && i->expire > ev_now ()) 203 // request data
156 { 204 rand_fill (snd_auth.rsa);
157 memcpy (&chg, &i->chg, sizeof chg); 205 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
158 206
159 erase (i); 207 // eventual response data
160 return true; 208 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
161 }
162 } 209 }
163 210
164 if (!cleaner.is_active ()) 211 // 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; 212 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} 213}
208 214
209////////////////////////////////////////////////////////////////////////////// 215//////////////////////////////////////////////////////////////////////////////
210 216
211pkt_queue::pkt_queue (double max_ttl, int max_queue) 217pkt_queue::pkt_queue (double max_ttl, int max_queue)
… …
225 delete p; 231 delete p;
226 232
227 delete [] queue; 233 delete [] queue;
228} 234}
229 235
236void
230void pkt_queue::expire_cb (ev::timer &w, int revents) 237pkt_queue::expire_cb (ev::timer &w, int revents)
231{ 238{
232 ev_tstamp expire = ev_now () - max_ttl; 239 ev_tstamp expire = ev_now () - max_ttl;
233 240
234 for (;;) 241 for (;;)
235 { 242 {
… …
246 253
247 delete get (); 254 delete get ();
248 } 255 }
249} 256}
250 257
258void
251void pkt_queue::put (net_packet *p) 259pkt_queue::put (net_packet *p)
252{ 260{
253 ev_tstamp now = ev_now (); 261 ev_tstamp now = ev_now ();
254 262
255 // start expiry timer 263 // start expiry timer
256 if (empty ()) 264 if (empty ())
… …
265 queue[i].tstamp = now; 273 queue[i].tstamp = now;
266 274
267 i = ni; 275 i = ni;
268} 276}
269 277
270net_packet *pkt_queue::get () 278net_packet *
279pkt_queue::get ()
271{ 280{
272 if (empty ()) 281 if (empty ())
273 return 0; 282 return 0;
274 283
275 net_packet *p = queue[j].pkt; 284 net_packet *p = queue[j].pkt;
… …
299 308
300 bool can (const sockinfo &si) { return can((u32)si.host); } 309 bool can (const sockinfo &si) { return can((u32)si.host); }
301 bool can (u32 host); 310 bool can (u32 host);
302}; 311};
303 312
304net_rate_limiter auth_rate_limiter, reset_rate_limiter; 313static net_rate_limiter auth_rate_limiter, reset_rate_limiter;
305 314
315bool
306bool net_rate_limiter::can (u32 host) 316net_rate_limiter::can (u32 host)
307{ 317{
308 iterator i; 318 iterator i;
309 319
310 for (i = begin (); i != end (); ) 320 for (i = begin (); i != end (); )
311 if (i->host == host) 321 if (i->host == host)
… …
356 } 366 }
357} 367}
358 368
359///////////////////////////////////////////////////////////////////////////// 369/////////////////////////////////////////////////////////////////////////////
360 370
361unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE]; 371void
362
363void hmac_packet::hmac_gen (crypto_ctx *ctx) 372hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
364{ 373{
365 unsigned int xlen;
366
367 HMAC_CTX *hctx = &ctx->hctx; 374 HMAC_CTX *hctx = &ctx->hctx;
368 375
369 HMAC_Init_ex (hctx, 0, 0, 0, 0); 376 require101 (HMAC_Init_ex (hctx, 0, 0, 0, 0));
370 HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), 377 require101 (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet)));
371 len - sizeof (hmac_packet)); 378 require101 (HMAC_Final (hctx, hmac_digest, 0));
372 HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen);
373} 379}
374 380
375void 381void
376hmac_packet::hmac_set (crypto_ctx *ctx) 382hmac_packet::hmac_set (crypto_ctx *ctx)
377{ 383{
378 hmac_gen (ctx); 384 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
379 385 hmac_gen (ctx, hmac_digest);
380 memcpy (hmac, hmac_digest, HMACLENGTH); 386 memcpy (hmac, hmac_digest, HMACLENGTH);
381} 387}
382 388
383bool 389bool
384hmac_packet::hmac_chk (crypto_ctx *ctx) 390hmac_packet::hmac_chk (crypto_ctx *ctx)
385{ 391{
386 hmac_gen (ctx); 392 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
387 393 hmac_gen (ctx, hmac_digest);
388 return !memcmp (hmac, hmac_digest, HMACLENGTH); 394 return slow_memeq (hmac, hmac_digest, HMACLENGTH);
389} 395}
390 396
397void
391void vpn_packet::set_hdr (ptype type_, unsigned int dst) 398vpn_packet::set_hdr (ptype type_, unsigned int dst)
392{ 399{
393 type = type_; 400 type = type_;
394 401
395 int src = THISNODE->id; 402 int src = THISNODE->id;
396 403
… …
401 408
402#define MAXVPNDATA (MAX_MTU - 6 - 6) 409#define MAXVPNDATA (MAX_MTU - 6 - 6)
403#define DATAHDR (sizeof (u32) + RAND_SIZE) 410#define DATAHDR (sizeof (u32) + RAND_SIZE)
404 411
405struct vpndata_packet : vpn_packet 412struct vpndata_packet : vpn_packet
413{
414 u8 data[MAXVPNDATA + DATAHDR]; // seqno
415
416 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
417 tap_packet *unpack (connection *conn, u32 &seqno);
418
419private:
420 const u32 data_hdr_size () const
406 { 421 {
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; 422 return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR;
416 }
417 }; 423 }
424};
418 425
419void 426void
420vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno) 427vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno)
421{ 428{
422 EVP_CIPHER_CTX *cctx = &conn->octx->cctx; 429 EVP_CIPHER_CTX *cctx = &conn->octx->cctx;
… …
424 ptype type = PT_DATA_UNCOMPRESSED; 431 ptype type = PT_DATA_UNCOMPRESSED;
425 432
426#if ENABLE_COMPRESSION 433#if ENABLE_COMPRESSION
427 u8 cdata[MAX_MTU]; 434 u8 cdata[MAX_MTU];
428 435
429 if (conn->features & ENABLE_COMPRESSION) 436 if (conn->features & FEATURE_COMPRESSION)
430 { 437 {
431 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7); 438 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7);
432 439
433 if (cl) 440 if (cl)
434 { 441 {
… …
440 d[1] = cl; 447 d[1] = cl;
441 } 448 }
442 } 449 }
443#endif 450#endif
444 451
445 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); 452 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 1));
446 453
447 struct { 454 struct {
448#if RAND_SIZE 455#if RAND_SIZE
449 u8 rnd[RAND_SIZE]; 456 u8 rnd[RAND_SIZE];
450#endif 457#endif
451 u32 seqno; 458 u32 seqno;
452 } datahdr; 459 } datahdr;
453 460
454 datahdr.seqno = ntohl (seqno); 461 datahdr.seqno = ntohl (seqno);
455#if RAND_SIZE 462#if RAND_SIZE
456 RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE); 463 // NB: a constant (per session) random prefix
464 // is likely enough, but we don't take any chances.
465 conn->oiv.get (datahdr.rnd, RAND_SIZE);
457#endif 466#endif
458 467
459 require (EVP_EncryptUpdate (cctx, 468 require (EVP_EncryptUpdate (cctx,
460 (unsigned char *) data + outl, &outl2, 469 (unsigned char *) data + outl, &outl2,
461 (unsigned char *) &datahdr, DATAHDR)); 470 (unsigned char *) &datahdr, DATAHDR));
… …
483 int outl = 0, outl2; 492 int outl = 0, outl2;
484 tap_packet *p = new tap_packet; 493 tap_packet *p = new tap_packet;
485 u8 *d; 494 u8 *d;
486 u32 l = len - data_hdr_size (); 495 u32 l = len - data_hdr_size ();
487 496
488 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); 497 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 0));
489 498
490#if ENABLE_COMPRESSION 499#if ENABLE_COMPRESSION
491 u8 cdata[MAX_MTU]; 500 u8 cdata[MAX_MTU];
492 501
493 if (type == PT_DATA_COMPRESSED) 502 if (type == PT_DATA_COMPRESSED)
494 d = cdata; 503 d = cdata;
495 else 504 else
496#endif 505#endif
497 d = &(*p)[6 + 6 - DATAHDR]; 506 d = &(*p)[6 + 6] - DATAHDR;
498 507
499 /* this overwrites part of the src mac, but we fix that later */ 508 // we play do evil games with the struct layout atm.
509 // pending better solutions, we at least do some verification.
510 // this is fine, as we left ISO territory long ago.
511 require (DATAHDR <= 16);
512 require ((u8 *)(&p->len + 1) == &(*p)[0]);
513
514 // this can overwrite the len/dst/src fields
500 require (EVP_DecryptUpdate (cctx, 515 require (EVP_DecryptUpdate (cctx,
501 d, &outl2, 516 d, &outl2,
502 (unsigned char *)&data, len - data_hdr_size ())); 517 (unsigned char *)&data, len - data_hdr_size ()));
503 outl += outl2; 518 outl += outl2;
504 519
… …
535 } 550 }
536}; 551};
537 552
538struct config_packet : vpn_packet 553struct config_packet : vpn_packet
539{ 554{
540 // actually, hmaclen cannot be checked because the hmac 555 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; 556 u8 prot_major, prot_minor, randsize;
544 u8 flags, challengelen, features, pad3; 557 u8 flags, features, pad6, pad7, pad8;
545 u32 cipher_nid, digest_nid, hmac_nid; 558 u32 cipher_nid, mac_nid, auth_nid;
546 559
547 void setup (ptype type, int dst); 560 void setup (ptype type, int dst);
548 bool chk_config () const; 561 bool chk_config (const conf_node *conf, const sockinfo &rsi) const;
549 562
550 static u8 get_features () 563 static u8 get_features ()
551 { 564 {
552 u8 f = 0; 565 u8 f = 0;
553#if ENABLE_COMPRESSION 566#if ENABLE_COMPRESSION
… …
561#endif 574#endif
562 return f; 575 return f;
563 } 576 }
564}; 577};
565 578
579void
566void config_packet::setup (ptype type, int dst) 580config_packet::setup (ptype type, int dst)
567{ 581{
568 prot_major = PROTOCOL_MAJOR; 582 prot_major = PROTOCOL_MAJOR;
569 prot_minor = PROTOCOL_MINOR; 583 prot_minor = PROTOCOL_MINOR;
570 randsize = RAND_SIZE; 584 randsize = RAND_SIZE;
571 hmaclen = HMACLENGTH;
572 flags = 0; 585 flags = 0;
573 challengelen = sizeof (rsachallenge);
574 features = get_features (); 586 features = get_features ();
575 587
588 strncpy ((char *)serial, conf.serial, sizeof (serial));
589
576 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 590 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
577 digest_nid = htonl (EVP_MD_type (RSA_HASH));
578 hmac_nid = htonl (EVP_MD_type (DIGEST)); 591 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ()));
592 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ()));
579 593
580 len = sizeof (*this) - sizeof (net_packet); 594 len = sizeof (*this) - sizeof (net_packet);
581 set_hdr (type, dst); 595 set_hdr (type, dst);
582} 596}
583 597
584bool config_packet::chk_config () const 598bool
599config_packet::chk_config (const conf_node *conf, const sockinfo &rsi) const
585{ 600{
586 if (prot_major != PROTOCOL_MAJOR) 601 if (prot_major != PROTOCOL_MAJOR)
587 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR); 602 slog (L_WARN, _("%s(%s): major version mismatch (remote %d <=> local %d)"),
603 conf->nodename, (const char *)rsi, prot_major, PROTOCOL_MAJOR);
588 else if (randsize != RAND_SIZE) 604 else if (randsize != RAND_SIZE)
589 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE); 605 slog (L_WARN, _("%s(%s): rand size mismatch (remote %d <=> local %d)"),
590 else if (hmaclen != HMACLENGTH) 606 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))) 607 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)); 608 slog (L_WARN, _("%s(%s): cipher algo mismatch (remote %x <=> local %x)"),
596 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH))) 609 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))) 610 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)); 611 slog (L_WARN, _("%s(%s): mac algo mismatch (remote %x <=> local %x)"),
612 conf->nodename, (const char *)rsi, ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ()));
613 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ())))
614 slog (L_WARN, _("%s(%s): auth algo mismatch (remote %x <=> local %x)"),
615 conf->nodename, (const char *)rsi, ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ()));
600 else 616 else
617 {
618 int cmp = memcmp (serial, ::conf.serial, sizeof (serial));
619
620 if (cmp > 0)
621 slog (L_WARN, _("%s(%s): remote serial newer than local serial - outdated config?"),
622 conf->nodename, (const char *)rsi);
623 else if (cmp == 0)
601 return true; 624 return true;
625 }
602 626
603 return false; 627 return false;
604} 628}
605 629
606struct auth_req_packet : config_packet 630struct auth_req_packet : config_packet // UNPROTECTED
607{ 631{
608 char magic[8]; 632 char magic[8];
609 u8 initiate; // false if this is just an automatic reply 633 u8 initiate; // false if this is just an automatic reply
610 u8 protocols; // supported protocols (will be patched on forward) 634 u8 protocols; // supported protocols (will be patched on forward)
611 u8 pad2, pad3; 635 u8 pad2, pad3;
612 rsaid id; 636 auth_encr encr;
613 rsaencrdata encr;
614 637
615 auth_req_packet (int dst, bool initiate_, u8 protocols_) 638 auth_req_packet (int dst, bool initiate_, u8 protocols_)
616 { 639 {
617 config_packet::setup (PT_AUTH_REQ, dst); 640 config_packet::setup (PT_AUTH_REQ, dst);
618 strncpy (magic, MAGIC, 8); 641 memcpy (magic, MAGIC, 8);
619 initiate = !!initiate_; 642 initiate = !!initiate_;
620 protocols = protocols_; 643 protocols = protocols_;
621 644
622 len = sizeof (*this) - sizeof (net_packet); 645 len = sizeof (*this) - sizeof (net_packet);
623 } 646 }
624}; 647};
625 648
626struct auth_res_packet : config_packet 649struct auth_res_packet : vpn_packet // UNPROTECTED
627{ 650{
628 rsaid id;
629 u8 pad1, pad2, pad3;
630 u8 response_len; // encrypted length
631 rsaresponse response; 651 auth_response response;
632 652
633 auth_res_packet (int dst) 653 auth_res_packet (int dst)
634 { 654 {
635 config_packet::setup (PT_AUTH_RES, dst); 655 set_hdr (PT_AUTH_RES, dst);
636 656
637 len = sizeof (*this) - sizeof (net_packet); 657 len = sizeof (*this) - sizeof (net_packet);
638 } 658 }
639}; 659};
640 660
… …
670}; 690};
671 691
672///////////////////////////////////////////////////////////////////////////// 692/////////////////////////////////////////////////////////////////////////////
673 693
674void 694void
675connection::connection_established () 695connection::connection_established (const sockinfo &rsi)
676{ 696{
677 slog (L_TRACE, _("%s: possible connection establish (ictx %d, octx %d)"), conf->nodename, !!ictx, !!octx); 697 if (!have_snd_auth || !have_rcv_auth)
698 return;
678 699
679 if (ictx && octx) 700 si = rsi;
701 protocol = rsi.prot;
702
703 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
704 conf->nodename, (const char *)rsi,
705 vpn->can_direct (THISNODE, conf) ? "direct" : "forwarded",
706 PROTOCOL_MAJOR, prot_minor);
707
708 if (::conf.script_node_up)
709 {
710 run_script_cb *cb = new run_script_cb;
711 cb->set<connection, &connection::script_node_up> (this);
712 run_script_queued (cb, _("node-up command execution failed, continuing."));
680 { 713 }
714
715 delete ictx; ictx = new crypto_ctx (rcv_auth, snd_auth, rcv_ecdh_a, rcv_auth.ecdh, 0);
716 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff);
717
718 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1);
719 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff;
720
721 oiv.reset ();
722
681 // make sure rekeying timeouts are slightly asymmetric 723 // make sure rekeying timeouts are slightly asymmetric
682 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0); 724 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
683 rekey.start (rekey_interval, rekey_interval); 725 rekey.start (rekey_interval, rekey_interval);
726
727 hmac_error = 0.;
728
684 keepalive.start (::conf.keepalive); 729 keepalive.start (::conf.keepalive);
685 730
686 // send queued packets 731 // send queued packets
687 if (ictx && octx)
688 {
689 while (tap_packet *p = (tap_packet *)data_queue.get ()) 732 while (tap_packet *p = (tap_packet *)data_queue.get ())
690 { 733 {
691 if (p->len) send_data_packet (p); 734 if (p->len) send_data_packet (p);
692 delete p; 735 delete p;
693 } 736 }
694 737
695 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) 738 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
696 { 739 {
697 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); 740 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
698 delete p; 741 delete p;
699 } 742 }
700 }
701 743
702 vpn->connection_established (this); 744 vpn->connection_established (this);
703 }
704 else
705 {
706 retry_cnt = 0;
707 establish_connection.start (5);
708 keepalive.stop ();
709 rekey.stop ();
710 }
711} 745}
712 746
713void 747void
714connection::reset_si () 748connection::reset_si ()
715{ 749{
… …
720 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename); 754 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename);
721 protocol = 0; 755 protocol = 0;
722 } 756 }
723 757
724 si.set (conf, protocol); 758 si.set (conf, protocol);
725
726 is_direct = si.valid ();
727} 759}
728 760
729// ensure sockinfo is valid, forward if necessary 761// ensure sockinfo is valid, forward if necessary
730const sockinfo & 762const sockinfo &
731connection::forward_si (const sockinfo &si) const 763connection::forward_si (const sockinfo &si) const
… …
750 782
751void 783void
752connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) 784connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
753{ 785{
754 if (!vpn->send_vpn_packet (pkt, si, tos)) 786 if (!vpn->send_vpn_packet (pkt, si, tos))
755 reset_connection (); 787 reset_connection ("packet send error");
756} 788}
757 789
758void 790void
759connection::send_ping (const sockinfo &si, u8 pong) 791connection::send_ping (const sockinfo &si, u8 pong)
760{ 792{
761 ping_packet *pkt = new ping_packet; 793 ping_packet *pkt = new ping_packet;
762 794
763 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING); 795 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
764 796
765 slog (L_TRACE, ">>%d %s [%s]", conf->id, pong ? "PT_PONG" : "PT_PING", (const char *)si); 797 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si);
766
767 send_vpn_packet (pkt, si, IPTOS_LOWDELAY); 798 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
768 799
769 delete pkt; 800 delete pkt;
770} 801}
771 802
… …
786void 817void
787connection::send_auth_request (const sockinfo &si, bool initiate) 818connection::send_auth_request (const sockinfo &si, bool initiate)
788{ 819{
789 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); 820 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
790 821
791 rsachallenge chg; 822 generate_auth_data ();
792 rsa_cache.gen (pkt->id, chg);
793 rsa_encrypt (conf->rsa_key, chg, pkt->encr); 823 auth_encrypt (conf->rsa_key, snd_auth, pkt->encr);
794 824
795 slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si); 825 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 826 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
798 827
799 delete pkt; 828 delete pkt;
800} 829}
801 830
802void 831void
803connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 832connection::send_auth_response (const sockinfo &si)
804{ 833{
805 auth_res_packet *pkt = new auth_res_packet (conf->id); 834 auth_res_packet *pkt = new auth_res_packet (conf->id);
806 835
807 pkt->id = id; 836 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof rcv_ecdh_b);
837 auth_hash (rcv_auth, rcv_ecdh_b, pkt->response.mac);
808 838
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); 839 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 840 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly
816 841
817 delete pkt; 842 delete pkt;
818} 843}
819 844
820void 845void
821connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols) 846connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols)
822{ 847{
823 slog (L_TRACE, ">>%d PT_CONNECT_INFO(%d,%s)", 848 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s,p%02x)", conf->nodename,
824 conf->id, rid, (const char *)rsi); 849 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi,
850 conf->protocols);
825 851
826 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols); 852 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols);
827 853
828 r->hmac_set (octx); 854 r->hmac_set (octx);
829 send_vpn_packet (r, si); 855 send_vpn_packet (r, si);
… …
832} 858}
833 859
834inline void 860inline void
835connection::establish_connection_cb (ev::timer &w, int revents) 861connection::establish_connection_cb (ev::timer &w, int revents)
836{ 862{
837 if (!ictx 863 if (!(ictx && octx)
838 && conf != THISNODE 864 && conf != THISNODE
839 && connectmode != conf_node::C_NEVER 865 && connectmode != conf_node::C_NEVER
840 && connectmode != conf_node::C_DISABLED 866 && connectmode != conf_node::C_DISABLED
841 && !w.is_active ()) 867 && !w.is_active ())
842 { 868 {
843 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection 869 // 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. 870 // 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 ()) 871 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ())
846 { 872 {
847 reset_connection (); 873 reset_connection ("no demand");
848 return; 874 return;
849 } 875 }
850 876
851 last_establish_attempt = ev_now (); 877 last_establish_attempt = ev_now ();
852 878
… …
854 ? (retry_cnt & 3) + 1 880 ? (retry_cnt & 3) + 1
855 : 1 << (retry_cnt >> 2)); 881 : 1 << (retry_cnt >> 2));
856 882
857 reset_si (); 883 reset_si ();
858 884
859 bool slow = si.prot & PROT_SLOW; 885 bool slow = (si.prot & PROT_SLOW) || (conf->low_power || THISNODE->low_power);
860 886
861 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf)) 887 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf))
862 { 888 {
863 /*TODO*/ /* start the timer so we don't recurse endlessly */ 889 /*TODO*/ /* start the timer so we don't recurse endlessly */
864 w.start (1); 890 w.start (1);
… …
874 900
875 slow = slow || (dsi.prot & PROT_SLOW); 901 slow = slow || (dsi.prot & PROT_SLOW);
876 902
877 if (dsi.valid () && auth_rate_limiter.can (dsi)) 903 if (dsi.valid () && auth_rate_limiter.can (dsi))
878 { 904 {
879 if (retry_cnt < 4) 905 // use ping after the first few retries
906 // TODO: on rekeys, the other node might not interpret ping correctly,
907 // TODO: as it will still have a valid connection
908 if (retry_cnt < 4 && (!conf->low_power || THISNODE->low_power))
880 send_auth_request (dsi, true); 909 send_auth_request (dsi, true);
881 else 910 else
882 send_ping (dsi, 0); 911 send_ping (dsi, 0);
883 } 912 }
884 } 913 }
885 914
886 retry_int *= slow ? 8. : 0.9; 915 retry_int *= slow ? 4. : 0.9;
887 916
888 if (retry_int < conf->max_retry) 917 if (retry_int < conf->max_retry)
889 retry_cnt++; 918 retry_cnt++;
890 else 919 else
891 retry_int = conf->max_retry; 920 retry_int = conf->max_retry;
… …
893 w.start (retry_int); 922 w.start (retry_int);
894 } 923 }
895} 924}
896 925
897void 926void
898connection::reset_connection () 927connection::reset_connection (const char *reason)
899{ 928{
900 if (ictx && octx) 929 if (ictx && octx)
901 { 930 {
902 slog (L_INFO, _("%s(%s): connection lost"), 931 slog (L_INFO, _("%s(%s): connection lost (%s)"),
903 conf->nodename, (const char *)si); 932 conf->nodename, (const char *)si, reason);
904 933
905 if (::conf.script_node_down) 934 if (::conf.script_node_down)
906 { 935 {
907 run_script_cb *cb = new run_script_cb; 936 run_script_cb *cb = new run_script_cb;
908 cb->set<connection, &connection::script_node_down> (this); 937 cb->set<connection, &connection::script_node_down> (this);
… …
910 } 939 }
911 } 940 }
912 941
913 delete ictx; ictx = 0; 942 delete ictx; ictx = 0;
914 delete octx; octx = 0; 943 delete octx; octx = 0;
915#if ENABLE_DNS
916 dnsv4_reset_connection ();
917#endif
918 944
919 si.host = 0; 945 si.host = 0;
946
947 have_snd_auth = false;
948 have_rcv_auth = false;
949 auth_expire = 0.;
920 950
921 last_activity = 0.; 951 last_activity = 0.;
922 //last_si_change = 0.; 952 //last_si_change = 0.;
923 retry_cnt = 0; 953 retry_cnt = 0;
924 954
… …
931connection::shutdown () 961connection::shutdown ()
932{ 962{
933 if (ictx && octx) 963 if (ictx && octx)
934 send_reset (si); 964 send_reset (si);
935 965
936 reset_connection (); 966 reset_connection ("shutdown");
937} 967}
938 968
939// poor-man's rekeying 969// poor-man's rekeying
940inline void 970inline void
941connection::rekey_cb (ev::timer &w, int revents) 971connection::rekey_cb (ev::timer &w, int revents)
942{ 972{
943 reset_connection (); 973 reset_connection ("rekeying");
944 establish_connection (); 974 establish_connection ();
945} 975}
946 976
947void 977void
948connection::send_data_packet (tap_packet *pkt) 978connection::send_data_packet (tap_packet *pkt)
… …
965 995
966void 996void
967connection::post_inject_queue () 997connection::post_inject_queue ()
968{ 998{
969 // force a connection every now and when when packets are sent (max 1/s) 999 // force a connection every now and when when packets are sent (max 1/s)
970 if (ev_now () - last_establish_attempt >= 0.95) // arbitrary 1000 if (ev_now () - last_establish_attempt >= (conf->low_power || THISNODE->low_power ? 2.95 : 0.95)) // arbitrary
971 establish_connection.stop (); 1001 establish_connection.stop ();
972 1002
973 establish_connection (); 1003 establish_connection ();
974} 1004}
975 1005
… …
983 data_queue.put (new tap_packet (*pkt)); 1013 data_queue.put (new tap_packet (*pkt));
984 post_inject_queue (); 1014 post_inject_queue ();
985 } 1015 }
986} 1016}
987 1017
1018void
988void connection::inject_vpn_packet (vpn_packet *pkt, int tos) 1019connection::inject_vpn_packet (vpn_packet *pkt, int tos)
989{ 1020{
990 if (ictx && octx) 1021 if (ictx && octx)
991 send_vpn_packet (pkt, si, tos); 1022 send_vpn_packet (pkt, si, tos);
992 else 1023 else
993 { 1024 {
… …
999void 1030void
1000connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) 1031connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
1001{ 1032{
1002 last_activity = ev_now (); 1033 last_activity = ev_now ();
1003 1034
1004 slog (L_NOISE, "<<%d received packet type %d from %d to %d.", 1035 slog (L_NOISE, "%s >> received packet type %d from %d to %d.",
1005 conf->id, pkt->typ (), pkt->src (), pkt->dst ()); 1036 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ());
1006 1037
1007 if (connectmode == conf_node::C_DISABLED) 1038 if (connectmode == conf_node::C_DISABLED)
1008 return; 1039 return;
1009 1040
1010 switch (pkt->typ ()) 1041 switch (pkt->typ ())
1011 { 1042 {
1012 case vpn_packet::PT_PING: 1043 case vpn_packet::PT_PING:
1044 slog (L_TRACE, "%s >> PT_PING", conf->nodename);
1045
1013 // we send pings instead of auth packets after some retries, 1046 // we send pings instead of auth packets after some retries,
1014 // so reset the retry counter and establish a connection 1047 // so reset the retry counter and establish a connection
1015 // when we receive a ping. 1048 // when we receive a ping.
1016 if (!ictx) 1049 if (!ictx)
1017 { 1050 {
1018 if (auth_rate_limiter.can (rsi)) 1051 if (auth_rate_limiter.can (rsi))
1019 send_auth_request (rsi, true); 1052 send_auth_request (rsi, true);
1020 } 1053 }
1021 else 1054 else
1022 // we would love to change thre socket address here, but ping's aren't 1055 // we would love to change the socket address here, but ping's aren't
1023 // authenticated, so we best ignore it. 1056 // authenticated, so we best ignore it.
1024 send_ping (rsi, 1); // pong 1057 send_ping (rsi, 1); // pong
1025 1058
1026 break; 1059 break;
1027 1060
1028 case vpn_packet::PT_PONG: 1061 case vpn_packet::PT_PONG:
1062 slog (L_TRACE, "%s >> PT_PONG", conf->nodename);
1063
1064 // a PONG might mean that the other side doesn't really know
1065 // about our desire for communication.
1066 establish_connection ();
1029 break; 1067 break;
1030 1068
1031 case vpn_packet::PT_RESET: 1069 case vpn_packet::PT_RESET:
1070 slog (L_TRACE, "%s >> PT_RESET", conf->nodename);
1071
1072 if (ictx && octx)
1032 { 1073 {
1033 reset_connection (); 1074 reset_connection ("remote reset");
1034 1075
1035 config_packet *p = (config_packet *) pkt; 1076 config_packet *p = (config_packet *) pkt;
1036 1077
1037 if (!p->chk_config ()) 1078 if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
1038 {
1039 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node."),
1040 conf->nodename, (const char *)rsi);
1041 connectmode = conf_node::C_DISABLED;
1042 }
1043 else if (connectmode == conf_node::C_ALWAYS)
1044 establish_connection (); 1079 establish_connection ();
1045 } 1080 }
1081
1046 break; 1082 break;
1047 1083
1048 case vpn_packet::PT_AUTH_REQ: 1084 case vpn_packet::PT_AUTH_REQ:
1049 if (auth_rate_limiter.can (rsi)) 1085 if (auth_rate_limiter.can (rsi))
1050 { 1086 {
1051 auth_req_packet *p = (auth_req_packet *) pkt; 1087 auth_req_packet *p = (auth_req_packet *)pkt;
1052 1088
1053 slog (L_TRACE, "<<%d PT_AUTH_REQ(%d)", conf->id, p->initiate); 1089 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)",
1090 conf->nodename, p->initiate ? "initiate" : "reply",
1091 p->protocols, p->features);
1054 1092
1055 if (p->chk_config () && !strncmp (p->magic, MAGIC, 8)) 1093 if (memcmp (p->magic, MAGIC, 8))
1094 {
1095 slog (L_WARN, _("%s(%s): protocol magic mismatch - stray packet?"),
1096 conf->nodename, (const char *)rsi);
1097 }
1098 else if (p->chk_config (conf, rsi))
1056 { 1099 {
1057 if (p->prot_minor != PROTOCOL_MINOR) 1100 if (p->prot_minor != PROTOCOL_MINOR)
1058 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), 1101 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1059 conf->nodename, (const char *)rsi, 1102 conf->nodename, (const char *)rsi,
1060 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1103 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1061 1104
1062 if (p->initiate) 1105 if (p->initiate)
1106 {
1063 send_auth_request (rsi, false); 1107 send_auth_request (rsi, false);
1064 1108
1065 rsachallenge k; 1109 if (ictx && octx)
1110 reset_connection ("reconnect");
1111 }
1066 1112
1113 auth_data auth;
1114
1067 if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) 1115 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
1068 { 1116 {
1069 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), 1117 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
1070 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0)); 1118 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
1071 break;
1072 } 1119 }
1073 else 1120 else
1074 { 1121 {
1075 delete octx; 1122 bool chg = !have_rcv_auth || !slow_memeq (&rcv_auth, &auth, sizeof auth);
1076 1123
1077 octx = new crypto_ctx (k, 1); 1124 rcv_auth = auth;
1078 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 1125 have_rcv_auth = true;
1079 1126
1127 send_auth_response (rsi);
1128
1129 if (chg)
1130 {
1080 conf->protocols = p->protocols; 1131 conf->protocols = p->protocols;
1081 features = p->features & config_packet::get_features (); 1132 features = p->features & config_packet::get_features ();
1082 1133
1083 send_auth_response (rsi, p->id, k);
1084
1085 connection_established (); 1134 connection_established (rsi);
1086
1087 break; 1135 }
1088 } 1136 }
1137
1138 break;
1089 } 1139 }
1090 else
1091 slog (L_WARN, _("%s(%s): protocol mismatch."),
1092 conf->nodename, (const char *)rsi);
1093 1140
1094 send_reset (rsi); 1141 send_reset (rsi);
1095 } 1142 }
1096 1143
1097 break; 1144 break;
1098 1145
1099 case vpn_packet::PT_AUTH_RES: 1146 case vpn_packet::PT_AUTH_RES:
1100 { 1147 {
1101 auth_res_packet *p = (auth_res_packet *) pkt; 1148 auth_res_packet *p = (auth_res_packet *)pkt;
1102 1149
1103 slog (L_TRACE, "<<%d PT_AUTH_RES", conf->id); 1150 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
1104 1151
1105 if (p->chk_config ()) 1152 auth_mac local_mac;
1153 auth_hash (snd_auth, p->response.ecdh, local_mac);
1154
1155 if (!slow_memeq (&p->response.mac, local_mac, sizeof local_mac))
1106 { 1156 {
1107 if (p->prot_minor != PROTOCOL_MINOR)
1108 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1109 conf->nodename, (const char *)rsi,
1110 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1111
1112 rsachallenge chg;
1113
1114 if (!rsa_cache.find (p->id, chg))
1115 {
1116 slog (L_ERR, _("%s(%s): unrequested auth response, ignoring."), 1157 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
1117 conf->nodename, (const char *)rsi); 1158 conf->nodename, (const char *)rsi);
1118 break;
1119 } 1159 }
1120 else 1160 else if (!have_snd_auth)
1121 { 1161 {
1122 crypto_ctx *cctx = new crypto_ctx (chg, 0); 1162 memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
1123 1163
1124 if (!p->hmac_chk (cctx)) 1164 have_snd_auth = true;
1125 {
1126 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
1127 "could be an attack, or just corruption or a synchronization error."),
1128 conf->nodename, (const char *)rsi);
1129 break;
1130 }
1131 else
1132 {
1133 rsaresponse h;
1134
1135 rsa_hash (p->id, chg, h);
1136
1137 if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
1138 {
1139 prot_minor = p->prot_minor;
1140
1141 delete ictx; ictx = cctx;
1142
1143 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
1144
1145 si = rsi;
1146 protocol = rsi.prot;
1147
1148 slog (L_INFO, _("%s(%s): connection established, protocol version %d.%d."),
1149 conf->nodename, (const char *)rsi,
1150 p->prot_major, p->prot_minor);
1151
1152 connection_established (); 1165 connection_established (rsi);
1153
1154 if (::conf.script_node_up)
1155 {
1156 run_script_cb *cb = new run_script_cb;
1157 cb->set<connection, &connection::script_node_up> (this);
1158 run_script_queued (cb, _("node-up command execution failed, continuing."));
1159 }
1160
1161 break;
1162 }
1163 else
1164 slog (L_ERR, _("%s(%s): sent and received challenge do not match."),
1165 conf->nodename, (const char *)rsi);
1166 }
1167
1168 delete cctx;
1169 }
1170 } 1166 }
1171 } 1167 }
1172
1173 send_reset (rsi);
1174 break; 1168 break;
1175 1169
1176 case vpn_packet::PT_DATA_COMPRESSED: 1170 case vpn_packet::PT_DATA_COMPRESSED:
1177#if !ENABLE_COMPRESSION 1171#if !ENABLE_COMPRESSION
1178 send_reset (rsi); 1172 send_reset (rsi);
… …
1184 if (ictx && octx) 1178 if (ictx && octx)
1185 { 1179 {
1186 vpndata_packet *p = (vpndata_packet *)pkt; 1180 vpndata_packet *p = (vpndata_packet *)pkt;
1187 1181
1188 if (!p->hmac_chk (ictx)) 1182 if (!p->hmac_chk (ictx))
1183 {
1184 // rekeying often creates temporary hmac auth floods
1185 // we assume they don't take longer than a few seconds normally,
1186 // and suppress messages and resets during that time.
1187 //TODO: should be done per source address
1188 if (!hmac_error)
1189 {
1190 hmac_error = ev_now () + 3;
1191 break;
1192 }
1193 else if (hmac_error >= ev_now ())
1194 break; // silently suppress
1195 else
1196 {
1189 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" 1197 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
1190 "could be an attack, or just corruption or a synchronization error."), 1198 "could be an attack, or just corruption or a synchronization error."),
1191 conf->nodename, (const char *)rsi); 1199 conf->nodename, (const char *)rsi);
1200 // reset
1201 }
1202 }
1192 else 1203 else
1193 { 1204 {
1194 u32 seqno; 1205 u32 seqno;
1195 tap_packet *d = p->unpack (this, seqno); 1206 tap_packet *d = p->unpack (this, seqno);
1196 int seqclass = iseqno.seqno_classify (seqno); 1207 int seqclass = iseqno.seqno_classify (seqno);
1197 1208
1209 hmac_error = 0;
1210
1198 if (seqclass == 0) // ok 1211 if (seqclass == 0) // ok
1199 { 1212 {
1200 vpn->tap->send (d); 1213 vpn->tap->send (d);
1201 1214
1202 if (si != rsi) 1215 if (si != rsi)
1203 { 1216 {
1204 // fast re-sync on source address changes, useful especially for tcp/ip 1217 // fast re-sync on source address changes, useful especially for tcp/ip
1205 //if (last_si_change < ev_now () + 5.) 1218 //if (last_si_change < ev_now () + 5.)
1206 // { 1219 // {
1220 slog (L_INFO, _("%s(%s): changing socket address to %s."),
1221 conf->nodename, (const char *)si, (const char *)rsi);
1222
1207 si = rsi; 1223 si = rsi;
1208 1224
1209 slog (L_INFO, _("%s(%s): socket address changed to %s."), 1225 if (::conf.script_node_change)
1210 conf->nodename, (const char *)si, (const char *)rsi); 1226 {
1227 run_script_cb *cb = new run_script_cb;
1228 cb->set<connection, &connection::script_node_change> (this);
1229 run_script_queued (cb, _("node-change command execution failed, continuing."));
1230 }
1231
1211 // } 1232 // }
1212 //else 1233 //else
1213 // slog (L_INFO, _("%s(%s): accepted packet from %s, not (yet) redirecting traffic."), 1234 // slog (L_INFO, _("%s(%s): accepted packet from %s, not (yet) redirecting traffic."),
1214 // conf->nodename, (const char *)si, (const char *)rsi); 1235 // conf->nodename, (const char *)si, (const char *)rsi);
1215 } 1236 }
1216 } 1237 }
1217 else if (seqclass == 1) // silently ignore 1238 else if (seqclass == 1) // far history
1239 slog (L_ERR, _("received very old packet (received %08lx, expected %08lx). "
1240 "possible replay attack, or just packet duplication/delay, ignoring."), seqno, iseqno.seq + 1);
1241 else if (seqclass == 2) // in-window duplicate, happens often on wireless
1218 slog (L_ERR, _("received duplicate packet (received %08lx, expected %08lx)\n" 1242 slog (L_DEBUG, _("received recent duplicated packet (received %08lx, expected %08lx). "
1219 "possible replay attack, or just packet duplication, ignoring."), seqno, iseqno.seq + 1); 1243 "possible replay attack, or just packet duplication, ignoring."), seqno, iseqno.seq + 1);
1220 else if (seqclass == 2) // reset 1244 else if (seqclass == 3) // reset
1221 { 1245 {
1222 slog (L_ERR, _("received duplicate or out-of-sync packet (received %08lx, expected %08lx)\n" 1246 slog (L_ERR, _("received out-of-sync (far future) packet (received %08lx, expected %08lx). "
1223 "possible replay attack, or just massive packet loss, resetting connection."), seqno, iseqno.seq + 1); 1247 "probably just massive packet loss, sending reset."), seqno, iseqno.seq + 1);
1224 send_reset (rsi); 1248 send_reset (rsi);
1225 } 1249 }
1226 1250
1227 delete d; 1251 delete d;
1228 break; 1252 break;
… …
1233 break; 1257 break;
1234 1258
1235 case vpn_packet::PT_CONNECT_REQ: 1259 case vpn_packet::PT_CONNECT_REQ:
1236 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) 1260 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
1237 { 1261 {
1238 connect_req_packet *p = (connect_req_packet *) pkt; 1262 connect_req_packet *p = (connect_req_packet *)pkt;
1239 1263
1240 if (p->id > 0 && p->id <= vpn->conns.size ()) 1264 if (p->id > 0 && p->id <= vpn->conns.size ())
1241 { 1265 {
1242 connection *c = vpn->conns[p->id - 1]; 1266 connection *c = vpn->conns[p->id - 1];
1243 conf->protocols = p->protocols; 1267 conf->protocols = p->protocols;
1244 1268
1245 slog (L_TRACE, "<<%d PT_CONNECT_REQ(%d) [%d]", 1269 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s,p%02x) [%d]",
1270 conf->nodename, vpn->conns[p->id - 1]->conf->nodename,
1271 p->protocols,
1246 conf->id, p->id, c->ictx && c->octx); 1272 c->ictx && c->octx);
1247 1273
1248 if (c->ictx && c->octx) 1274 if (c->ictx && c->octx)
1249 { 1275 {
1250 // send connect_info packets to both sides, in case one is 1276 // send connect_info packets to both sides, in case one is
1251 // behind a nat firewall (or both ;) 1277 // behind a nat firewall (or both ;)
… …
1274 1300
1275 c->conf->protocols = p->protocols; 1301 c->conf->protocols = p->protocols;
1276 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf)); 1302 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf));
1277 p->si.upgrade_protocol (protocol, c->conf); 1303 p->si.upgrade_protocol (protocol, c->conf);
1278 1304
1279 slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)", 1305 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s,protocols=%02x,protocol=%02x,upgradable=%02x) [%d]",
1280 conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx); 1306 conf->nodename,
1307 vpn->conns[p->id - 1]->conf->nodename,
1308 (const char *)p->si,
1309 p->protocols,
1310 protocol,
1311 p->si.supported_protocols (c->conf),
1312 !c->ictx && !c->octx);
1281 1313
1282 const sockinfo &dsi = forward_si (p->si); 1314 const sockinfo &dsi = forward_si (p->si);
1283 1315
1284 if (dsi.valid ()) 1316 if (dsi.valid ())
1285 c->send_auth_request (dsi, true); 1317 c->send_auth_request (dsi, true);
1318 else
1319 slog (L_INFO, "connect info for %s received (%s), but still unable to contact.",
1320 vpn->conns[p->id - 1]->conf->nodename,
1321 (const char *)p->si);
1286 } 1322 }
1287 else 1323 else
1288 slog (L_WARN, 1324 slog (L_WARN,
1289 _("received authenticated connection request from unknown node #%d, config file mismatch?"), 1325 _("received authenticated connection request from unknown node #%d, config file mismatch?"),
1290 p->id); 1326 p->id);
… …
1299} 1335}
1300 1336
1301inline void 1337inline void
1302connection::keepalive_cb (ev::timer &w, int revents) 1338connection::keepalive_cb (ev::timer &w, int revents)
1303{ 1339{
1304 if (ev_now () >= last_activity + ::conf.keepalive + 30) 1340 ev_tstamp when = last_activity + ::conf.keepalive - ev::now ();
1341
1342 if (when >= 0)
1343 w.start (when);
1344 else if (when < -15)
1305 { 1345 {
1306 reset_connection (); 1346 reset_connection ("keepalive overdue");
1307 establish_connection (); 1347 establish_connection ();
1308 } 1348 }
1309 else if (ev_now () < last_activity + ::conf.keepalive)
1310 w.start (last_activity + ::conf.keepalive - ev::now ());
1311 else if (conf->connectmode != conf_node::C_ONDEMAND 1349 else if (conf->connectmode != conf_node::C_ONDEMAND
1312 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1350 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1313 { 1351 {
1352 w.start (3);
1314 send_ping (si); 1353 send_ping (si);
1315 w.start (5);
1316 } 1354 }
1317 else if (ev_now () < last_activity + ::conf.keepalive + 10) 1355 else if (when >= -10)
1318 // hold ondemand connections implicitly a few seconds longer 1356 // hold ondemand connections implicitly a few seconds longer
1319 // should delete octx, though, or something like that ;) 1357 // should delete octx, though, or something like that ;)
1320 w.start (last_activity + ::conf.keepalive + 10 - ev::now ()); 1358 w.start (when + 10);
1321 else 1359 else
1322 reset_connection (); 1360 reset_connection ("keepalive timeout");
1323} 1361}
1324 1362
1363void
1325void connection::send_connect_request (int id) 1364connection::send_connect_request (int id)
1326{ 1365{
1327 connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols); 1366 connect_req_packet *p = new connect_req_packet (conf->id, id, THISNODE->protocols);
1328 1367
1329 slog (L_TRACE, ">>%d PT_CONNECT_REQ(%d)", conf->id, id); 1368 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s,p%02x)",
1369 conf->nodename, vpn->conns[id - 1]->conf->nodename,
1370 THISNODE->protocols);
1330 p->hmac_set (octx); 1371 p->hmac_set (octx);
1331 send_vpn_packet (p, si); 1372 send_vpn_packet (p, si);
1332 1373
1333 delete p; 1374 delete p;
1334} 1375}
1335 1376
1377void
1336void connection::script_init_env (const char *ext) 1378connection::script_init_env (const char *ext)
1337{ 1379{
1338 char *env; 1380 char *env;
1339 asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env); 1381 asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env);
1340 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env); 1382 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env);
1341 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext, 1383 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext,
1342 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8, 1384 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8,
1343 conf->id & 0xff); putenv (env); 1385 conf->id & 0xff); putenv (env);
1344} 1386}
1345 1387
1388void
1346void connection::script_init_connect_env () 1389connection::script_init_connect_env ()
1347{ 1390{
1348 vpn->script_init_env (); 1391 vpn->script_init_env ();
1349 1392
1350 char *env; 1393 char *env;
1351 asprintf (&env, "DESTID=%d", conf->id); putenv (env); 1394 asprintf (&env, "DESTID=%d", conf->id); putenv (env);
1395 asprintf (&env, "DESTSI=%s", (const char *)si); putenv (env);
1352 asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env); 1396 asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env);
1353 asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env); 1397 asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env);
1354 asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env); 1398 asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env);
1355} 1399}
1356 1400
1357inline const char * 1401inline const char *
1358connection::script_node_up () 1402connection::script_node_up ()
1359{ 1403{
… …
1364 char *filename; 1408 char *filename;
1365 asprintf (&filename, 1409 asprintf (&filename,
1366 "%s/%s", 1410 "%s/%s",
1367 confbase, 1411 confbase,
1368 ::conf.script_node_up ? ::conf.script_node_up : "node-up"); 1412 ::conf.script_node_up ? ::conf.script_node_up : "node-up");
1413
1414 return filename;
1415}
1416
1417inline const char *
1418connection::script_node_change ()
1419{
1420 script_init_connect_env ();
1421
1422 putenv ((char *)"STATE=change");
1423
1424 char *filename;
1425 asprintf (&filename,
1426 "%s/%s",
1427 confbase,
1428 ::conf.script_node_change ? ::conf.script_node_change : "node-change");
1369 1429
1370 return filename; 1430 return filename;
1371} 1431}
1372 1432
1373inline const char * 1433inline const char *
… …
1399 establish_connection.set<connection, &connection::establish_connection_cb> (this); 1459 establish_connection.set<connection, &connection::establish_connection_cb> (this);
1400 1460
1401 last_establish_attempt = 0.; 1461 last_establish_attempt = 0.;
1402 octx = ictx = 0; 1462 octx = ictx = 0;
1403 1463
1404 if (!conf->protocols) // make sure some protocol is enabled
1405 conf->protocols = PROT_UDPv4;
1406
1407 connectmode = conf->connectmode; 1464 connectmode = conf->connectmode;
1408 1465
1409 // queue a dummy packet to force an initial connection attempt 1466 // queue a dummy packet to force an initial connection attempt
1410 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) 1467 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
1411 vpn_queue.put (new net_packet); 1468 vpn_queue.put (new net_packet);
1412 1469
1413 reset_connection (); 1470 reset_connection ("startup");
1414} 1471}
1415 1472
1416connection::~connection () 1473connection::~connection ()
1417{ 1474{
1418 shutdown (); 1475 shutdown ();
1419} 1476}
1420 1477
1478void
1421void connection_init () 1479connection_init ()
1422{ 1480{
1423 auth_rate_limiter.clear (); 1481 auth_rate_limiter.clear ();
1424 reset_rate_limiter.clear (); 1482 reset_rate_limiter.clear ();
1425} 1483}
1426 1484

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