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Comparing gvpe/src/connection.C (file contents):
Revision 1.85 by pcg, Tue Jul 28 00:42:14 2009 UTC vs.
Revision 1.109 by root, Fri Oct 11 07:56:07 2013 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_OLD "vped\xbd\xc6\xdb\x82" // 8 bytes of magic (still used in the protocol)
56#define MAGIC "gvpe\xbd\xc6\xdb\x82" // 8 bytes of magic (understood but not generated) 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
57 62
58#define ULTRA_FAST 1 63#define ULTRA_FAST 1
59#define HLOG 15 64#define HLOG 15
60#include "lzf/lzf.h" 65#include "lzf/lzf.h"
61#include "lzf/lzf_c.c" 66#include "lzf/lzf_c.c"
… …
64////////////////////////////////////////////////////////////////////////////// 69//////////////////////////////////////////////////////////////////////////////
65 70
66static std::queue< std::pair<run_script_cb *, const char *> > rs_queue; 71static std::queue< std::pair<run_script_cb *, const char *> > rs_queue;
67static ev::child rs_child_ev; 72static ev::child rs_child_ev;
68 73
74namespace
75{
69void // c++ requires external linkage here, apparently :( 76 void // c++ requires external linkage here, apparently :(
70rs_child_cb (ev::child &w, int revents) 77 rs_child_cb (ev::child &w, int revents)
71{ 78 {
72 w.stop (); 79 w.stop ();
73 80
74 if (rs_queue.empty ()) 81 if (rs_queue.empty ())
75 return; 82 return;
76 83
77 pid_t pid = run_script (*rs_queue.front ().first, false); 84 pid_t pid = run_script (*rs_queue.front ().first, false);
78 if (pid) 85 if (pid)
79 { 86 {
80 w.set (pid); 87 w.set (pid);
81 w.start (); 88 w.start ();
82 } 89 }
83 else 90 else
84 slog (L_WARN, rs_queue.front ().second); 91 slog (L_WARN, rs_queue.front ().second);
85 92
86 delete rs_queue.front ().first; 93 delete rs_queue.front ().first;
87 rs_queue.pop (); 94 rs_queue.pop ();
88} 95 }
96};
89 97
90// despite the fancy name, this is quite a hack 98// despite the fancy name, this is quite a hack
91static void 99static void
92run_script_queued (run_script_cb *cb, const char *warnmsg) 100run_script_queued (run_script_cb *cb, const char *warnmsg)
93{ 101{
… …
105struct crypto_ctx 113struct crypto_ctx
106{ 114{
107 EVP_CIPHER_CTX cctx; 115 EVP_CIPHER_CTX cctx;
108 HMAC_CTX hctx; 116 HMAC_CTX hctx;
109 117
110 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);
111 ~crypto_ctx (); 119 ~crypto_ctx ();
112}; 120};
113 121
114crypto_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)
115{ 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
116 EVP_CIPHER_CTX_init (&cctx); 152 EVP_CIPHER_CTX_init (&cctx);
117 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));
118 HMAC_CTX_init (&hctx); 154 }
119 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
120} 155}
121 156
122crypto_ctx::~crypto_ctx () 157crypto_ctx::~crypto_ctx ()
123{ 158{
124 require (EVP_CIPHER_CTX_cleanup (&cctx)); 159 require (EVP_CIPHER_CTX_cleanup (&cctx));
125 HMAC_CTX_cleanup (&hctx); 160 HMAC_CTX_cleanup (&hctx);
126} 161}
127 162
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
128static void 190static void
129rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) 191auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
130{ 192{
131 EVP_MD_CTX ctx; 193 hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt
132 194 kdf.extract (&auth.rsa, sizeof (auth.rsa));
133 EVP_MD_CTX_init (&ctx); 195 kdf.extract_done ();
134 require (EVP_DigestInit (&ctx, RSA_HASH)); 196 kdf.expand (mac, sizeof mac, auth.ecdh, sizeof (auth.ecdh)); // use challenge ecdh b as info
135 require (EVP_DigestUpdate(&ctx, &chg, sizeof chg));
136 require (EVP_DigestUpdate(&ctx, &id, sizeof id));
137 require (EVP_DigestFinal (&ctx, (unsigned char *)&h, 0));
138 EVP_MD_CTX_cleanup (&ctx);
139} 197}
140 198
141struct rsa_entry 199void
200connection::generate_auth_data ()
142{ 201{
143 tstamp expire; 202 if (auth_expire < ev_now ())
144 rsaid id;
145 rsachallenge chg;
146};
147
148struct rsa_cache : list<rsa_entry>
149{
150 inline void cleaner_cb (ev::timer &w, int revents); ev::timer cleaner;
151
152 bool find (const rsaid &id, rsachallenge &chg)
153 {
154 for (iterator i = begin (); i != end (); ++i)
155 { 203 {
156 if (!memcmp (&id, &i->id, sizeof id) && i->expire > ev_now ()) 204 // request data
157 { 205 rand_fill (snd_auth.rsa);
158 memcpy (&chg, &i->chg, sizeof chg); 206 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
159 207
160 erase (i); 208 // eventual response data
161 return true; 209 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
162 }
163 } 210 }
164 211
165 if (!cleaner.is_active ()) 212 // every use prolongs the expiry
166 cleaner.again ();
167
168 return false;
169 }
170
171 void gen (rsaid &id, rsachallenge &chg)
172 {
173 rsa_entry e;
174
175 RAND_bytes ((unsigned char *)&id, sizeof id);
176 RAND_bytes ((unsigned char *)&chg, sizeof chg);
177
178 e.expire = ev_now () + RSA_TTL; 213 auth_expire = ev_now () + AUTH_TTL;
179 e.id = id;
180 memcpy (&e.chg, &chg, sizeof chg);
181
182 push_back (e);
183
184 if (!cleaner.is_active ())
185 cleaner.again ();
186 }
187
188 rsa_cache ()
189 {
190 cleaner.set<rsa_cache, &rsa_cache::cleaner_cb> (this);
191 cleaner.set (RSA_TTL, RSA_TTL);
192 }
193
194} rsa_cache;
195
196void rsa_cache::cleaner_cb (ev::timer &w, int revents)
197{
198 if (empty ())
199 w.stop ();
200 else
201 {
202 for (iterator i = begin (); i != end (); )
203 if (i->expire <= ev_now ())
204 i = erase (i);
205 else
206 ++i;
207 }
208} 214}
209 215
210////////////////////////////////////////////////////////////////////////////// 216//////////////////////////////////////////////////////////////////////////////
211 217
212pkt_queue::pkt_queue (double max_ttl, int max_queue) 218pkt_queue::pkt_queue (double max_ttl, int max_queue)
… …
226 delete p; 232 delete p;
227 233
228 delete [] queue; 234 delete [] queue;
229} 235}
230 236
237void
231void pkt_queue::expire_cb (ev::timer &w, int revents) 238pkt_queue::expire_cb (ev::timer &w, int revents)
232{ 239{
233 ev_tstamp expire = ev_now () - max_ttl; 240 ev_tstamp expire = ev_now () - max_ttl;
234 241
235 for (;;) 242 for (;;)
236 { 243 {
… …
247 254
248 delete get (); 255 delete get ();
249 } 256 }
250} 257}
251 258
259void
252void pkt_queue::put (net_packet *p) 260pkt_queue::put (net_packet *p)
253{ 261{
254 ev_tstamp now = ev_now (); 262 ev_tstamp now = ev_now ();
255 263
256 // start expiry timer 264 // start expiry timer
257 if (empty ()) 265 if (empty ())
… …
266 queue[i].tstamp = now; 274 queue[i].tstamp = now;
267 275
268 i = ni; 276 i = ni;
269} 277}
270 278
271net_packet *pkt_queue::get () 279net_packet *
280pkt_queue::get ()
272{ 281{
273 if (empty ()) 282 if (empty ())
274 return 0; 283 return 0;
275 284
276 net_packet *p = queue[j].pkt; 285 net_packet *p = queue[j].pkt;
… …
300 309
301 bool can (const sockinfo &si) { return can((u32)si.host); } 310 bool can (const sockinfo &si) { return can((u32)si.host); }
302 bool can (u32 host); 311 bool can (u32 host);
303}; 312};
304 313
305net_rate_limiter auth_rate_limiter, reset_rate_limiter; 314static net_rate_limiter auth_rate_limiter, reset_rate_limiter;
306 315
316bool
307bool net_rate_limiter::can (u32 host) 317net_rate_limiter::can (u32 host)
308{ 318{
309 iterator i; 319 iterator i;
310 320
311 for (i = begin (); i != end (); ) 321 for (i = begin (); i != end (); )
312 if (i->host == host) 322 if (i->host == host)
… …
357 } 367 }
358} 368}
359 369
360///////////////////////////////////////////////////////////////////////////// 370/////////////////////////////////////////////////////////////////////////////
361 371
362unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE]; 372void
363
364void hmac_packet::hmac_gen (crypto_ctx *ctx) 373hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
365{ 374{
366 unsigned int xlen;
367
368 HMAC_CTX *hctx = &ctx->hctx; 375 HMAC_CTX *hctx = &ctx->hctx;
369 376
370 HMAC_Init_ex (hctx, 0, 0, 0, 0); 377 require101 (HMAC_Init_ex (hctx, 0, 0, 0, 0));
371 HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), 378 require101 (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet)));
372 len - sizeof (hmac_packet)); 379 require101 (HMAC_Final (hctx, hmac_digest, 0));
373 HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen);
374} 380}
375 381
376void 382void
377hmac_packet::hmac_set (crypto_ctx *ctx) 383hmac_packet::hmac_set (crypto_ctx *ctx)
378{ 384{
379 hmac_gen (ctx); 385 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
380 386 hmac_gen (ctx, hmac_digest);
381 memcpy (hmac, hmac_digest, HMACLENGTH); 387 memcpy (hmac, hmac_digest, HMACLENGTH);
382} 388}
383 389
384bool 390bool
385hmac_packet::hmac_chk (crypto_ctx *ctx) 391hmac_packet::hmac_chk (crypto_ctx *ctx)
386{ 392{
387 hmac_gen (ctx); 393 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
388 394 hmac_gen (ctx, hmac_digest);
389 return !memcmp (hmac, hmac_digest, HMACLENGTH); 395 return !memcmp (hmac, hmac_digest, HMACLENGTH);
390} 396}
391 397
398void
392void vpn_packet::set_hdr (ptype type_, unsigned int dst) 399vpn_packet::set_hdr (ptype type_, unsigned int dst)
393{ 400{
394 type = type_; 401 type = type_;
395 402
396 int src = THISNODE->id; 403 int src = THISNODE->id;
397 404
… …
402 409
403#define MAXVPNDATA (MAX_MTU - 6 - 6) 410#define MAXVPNDATA (MAX_MTU - 6 - 6)
404#define DATAHDR (sizeof (u32) + RAND_SIZE) 411#define DATAHDR (sizeof (u32) + RAND_SIZE)
405 412
406struct 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
407 { 422 {
408 u8 data[MAXVPNDATA + DATAHDR]; // seqno
409
410 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
411 tap_packet *unpack (connection *conn, u32 &seqno);
412private:
413
414 const u32 data_hdr_size () const
415 {
416 return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR; 423 return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR;
417 }
418 }; 424 }
425};
419 426
420void 427void
421vpndata_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)
422{ 429{
423 EVP_CIPHER_CTX *cctx = &conn->octx->cctx; 430 EVP_CIPHER_CTX *cctx = &conn->octx->cctx;
… …
425 ptype type = PT_DATA_UNCOMPRESSED; 432 ptype type = PT_DATA_UNCOMPRESSED;
426 433
427#if ENABLE_COMPRESSION 434#if ENABLE_COMPRESSION
428 u8 cdata[MAX_MTU]; 435 u8 cdata[MAX_MTU];
429 436
430 if (conn->features & ENABLE_COMPRESSION) 437 if (conn->features & FEATURE_COMPRESSION)
431 { 438 {
432 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7); 439 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7);
433 440
434 if (cl) 441 if (cl)
435 { 442 {
… …
441 d[1] = cl; 448 d[1] = cl;
442 } 449 }
443 } 450 }
444#endif 451#endif
445 452
446 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); 453 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 1));
447 454
448 struct { 455 struct {
449#if RAND_SIZE 456#if RAND_SIZE
450 u8 rnd[RAND_SIZE]; 457 u8 rnd[RAND_SIZE];
451#endif 458#endif
452 u32 seqno; 459 u32 seqno;
453 } datahdr; 460 } datahdr;
454 461
455 datahdr.seqno = ntohl (seqno); 462 datahdr.seqno = ntohl (seqno);
456#if RAND_SIZE 463#if RAND_SIZE
457 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);
458#endif 467#endif
459 468
460 require (EVP_EncryptUpdate (cctx, 469 require (EVP_EncryptUpdate (cctx,
461 (unsigned char *) data + outl, &outl2, 470 (unsigned char *) data + outl, &outl2,
462 (unsigned char *) &datahdr, DATAHDR)); 471 (unsigned char *) &datahdr, DATAHDR));
… …
484 int outl = 0, outl2; 493 int outl = 0, outl2;
485 tap_packet *p = new tap_packet; 494 tap_packet *p = new tap_packet;
486 u8 *d; 495 u8 *d;
487 u32 l = len - data_hdr_size (); 496 u32 l = len - data_hdr_size ();
488 497
489 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); 498 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 0));
490 499
491#if ENABLE_COMPRESSION 500#if ENABLE_COMPRESSION
492 u8 cdata[MAX_MTU]; 501 u8 cdata[MAX_MTU];
493 502
494 if (type == PT_DATA_COMPRESSED) 503 if (type == PT_DATA_COMPRESSED)
495 d = cdata; 504 d = cdata;
496 else 505 else
497#endif 506#endif
498 d = &(*p)[6 + 6 - DATAHDR]; 507 d = &(*p)[6 + 6] - DATAHDR;
499 508
500 /* 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
501 require (EVP_DecryptUpdate (cctx, 516 require (EVP_DecryptUpdate (cctx,
502 d, &outl2, 517 d, &outl2,
503 (unsigned char *)&data, len - data_hdr_size ())); 518 (unsigned char *)&data, len - data_hdr_size ()));
504 outl += outl2; 519 outl += outl2;
505 520
… …
536 } 551 }
537}; 552};
538 553
539struct config_packet : vpn_packet 554struct config_packet : vpn_packet
540{ 555{
541 // actually, hmaclen cannot be checked because the hmac 556 u8 serial[SERIAL_SIZE];
542 // field comes before this data, so peers with other
543 // hmacs simply will not work.
544 u8 prot_major, prot_minor, randsize, hmaclen; 557 u8 prot_major, prot_minor, randsize;
545 u8 flags, challengelen, features, pad3; 558 u8 flags, features, pad6, pad7, pad8;
546 u32 cipher_nid, digest_nid, hmac_nid; 559 u32 cipher_nid, mac_nid, auth_nid;
547 560
548 void setup (ptype type, int dst); 561 void setup (ptype type, int dst);
549 bool chk_config () const; 562 bool chk_config (const conf_node *conf, const sockinfo &rsi) const;
550 563
551 static u8 get_features () 564 static u8 get_features ()
552 { 565 {
553 u8 f = 0; 566 u8 f = 0;
554#if ENABLE_COMPRESSION 567#if ENABLE_COMPRESSION
… …
562#endif 575#endif
563 return f; 576 return f;
564 } 577 }
565}; 578};
566 579
580void
567void config_packet::setup (ptype type, int dst) 581config_packet::setup (ptype type, int dst)
568{ 582{
569 prot_major = PROTOCOL_MAJOR; 583 prot_major = PROTOCOL_MAJOR;
570 prot_minor = PROTOCOL_MINOR; 584 prot_minor = PROTOCOL_MINOR;
571 randsize = RAND_SIZE; 585 randsize = RAND_SIZE;
572 hmaclen = HMACLENGTH;
573 flags = 0; 586 flags = 0;
574 challengelen = sizeof (rsachallenge);
575 features = get_features (); 587 features = get_features ();
576 588
589 strncpy ((char *)serial, conf.serial, sizeof (serial));
590
577 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 591 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
578 digest_nid = htonl (EVP_MD_type (RSA_HASH));
579 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 ()));
580 594
581 len = sizeof (*this) - sizeof (net_packet); 595 len = sizeof (*this) - sizeof (net_packet);
582 set_hdr (type, dst); 596 set_hdr (type, dst);
583} 597}
584 598
585bool config_packet::chk_config () const 599bool
600config_packet::chk_config (const conf_node *conf, const sockinfo &rsi) const
586{ 601{
587 if (prot_major != PROTOCOL_MAJOR) 602 if (prot_major != PROTOCOL_MAJOR)
588 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);
589 else if (randsize != RAND_SIZE) 605 else if (randsize != RAND_SIZE)
590 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)"),
591 else if (hmaclen != HMACLENGTH) 607 conf->nodename, (const char *)rsi, randsize, RAND_SIZE);
592 slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH);
593 else if (challengelen != sizeof (rsachallenge))
594 slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge));
595 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER))) 608 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER ())))
596 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)"),
597 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH))) 610 conf->nodename, (const char *)rsi, ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER ()));
598 slog (L_WARN, _("digest mismatch (remote %x <=> local %x)"), ntohl (digest_nid), EVP_MD_type (RSA_HASH));
599 else if (hmac_nid != htonl (EVP_MD_type (DIGEST))) 611 else if (mac_nid != htonl (EVP_MD_type (MAC_DIGEST ())))
600 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 ()));
601 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)
602 return true; 625 return true;
626 }
603 627
604 return false; 628 return false;
605} 629}
606 630
607struct auth_req_packet : config_packet 631struct auth_req_packet : config_packet // UNPROTECTED
608{ 632{
609 char magic[8]; 633 char magic[8];
610 u8 initiate; // false if this is just an automatic reply 634 u8 initiate; // false if this is just an automatic reply
611 u8 protocols; // supported protocols (will be patched on forward) 635 u8 protocols; // supported protocols (will be patched on forward)
612 u8 pad2, pad3; 636 u8 pad2, pad3;
613 rsaid id; 637 auth_encr encr;
614 rsaencrdata encr;
615 638
616 auth_req_packet (int dst, bool initiate_, u8 protocols_) 639 auth_req_packet (int dst, bool initiate_, u8 protocols_)
617 { 640 {
618 config_packet::setup (PT_AUTH_REQ, dst); 641 config_packet::setup (PT_AUTH_REQ, dst);
619 strncpy (magic, MAGIC_OLD, 8); 642 memcpy (magic, MAGIC, 8);
620 initiate = !!initiate_; 643 initiate = !!initiate_;
621 protocols = protocols_; 644 protocols = protocols_;
622 645
623 len = sizeof (*this) - sizeof (net_packet); 646 len = sizeof (*this) - sizeof (net_packet);
624 } 647 }
625}; 648};
626 649
627struct auth_res_packet : config_packet 650struct auth_res_packet : vpn_packet // UNPROTECTED
628{ 651{
629 rsaid id;
630 u8 pad1, pad2, pad3;
631 u8 response_len; // encrypted length
632 rsaresponse response; 652 auth_response response;
633 653
634 auth_res_packet (int dst) 654 auth_res_packet (int dst)
635 { 655 {
636 config_packet::setup (PT_AUTH_RES, dst); 656 set_hdr (PT_AUTH_RES, dst);
637 657
638 len = sizeof (*this) - sizeof (net_packet); 658 len = sizeof (*this) - sizeof (net_packet);
639 } 659 }
640}; 660};
641 661
… …
671}; 691};
672 692
673///////////////////////////////////////////////////////////////////////////// 693/////////////////////////////////////////////////////////////////////////////
674 694
675void 695void
676connection::connection_established () 696connection::connection_established (const sockinfo &rsi)
677{ 697{
678 slog (L_NOISE, _("%s: possible connection establish (ictx %d, octx %d)"), conf->nodename, !!ictx, !!octx); 698 if (!have_snd_auth || !have_rcv_auth)
699 return;
679 700
680 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."));
681 { 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
682 // make sure rekeying timeouts are slightly asymmetric 724 // make sure rekeying timeouts are slightly asymmetric
683 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);
684 rekey.start (rekey_interval, rekey_interval); 726 rekey.start (rekey_interval, rekey_interval);
727
728 hmac_error = 0.;
729
685 keepalive.start (::conf.keepalive); 730 keepalive.start (::conf.keepalive);
686 731
687 // send queued packets 732 // send queued packets
688 if (ictx && octx)
689 {
690 while (tap_packet *p = (tap_packet *)data_queue.get ()) 733 while (tap_packet *p = (tap_packet *)data_queue.get ())
691 { 734 {
692 if (p->len) send_data_packet (p); 735 if (p->len) send_data_packet (p);
693 delete p; 736 delete p;
694 } 737 }
695 738
696 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) 739 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
697 { 740 {
698 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); 741 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
699 delete p; 742 delete p;
700 } 743 }
701 }
702 744
703 vpn->connection_established (this); 745 vpn->connection_established (this);
704 }
705 else
706 {
707 retry_cnt = 0;
708 establish_connection.start (5);
709 keepalive.stop ();
710 rekey.stop ();
711 }
712} 746}
713 747
714void 748void
715connection::reset_si () 749connection::reset_si ()
716{ 750{
… …
721 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename); 755 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename);
722 protocol = 0; 756 protocol = 0;
723 } 757 }
724 758
725 si.set (conf, protocol); 759 si.set (conf, protocol);
726
727 is_direct = si.valid ();
728} 760}
729 761
730// ensure sockinfo is valid, forward if necessary 762// ensure sockinfo is valid, forward if necessary
731const sockinfo & 763const sockinfo &
732connection::forward_si (const sockinfo &si) const 764connection::forward_si (const sockinfo &si) const
… …
751 783
752void 784void
753connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) 785connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
754{ 786{
755 if (!vpn->send_vpn_packet (pkt, si, tos)) 787 if (!vpn->send_vpn_packet (pkt, si, tos))
756 reset_connection (); 788 reset_connection ("packet send error");
757} 789}
758 790
759void 791void
760connection::send_ping (const sockinfo &si, u8 pong) 792connection::send_ping (const sockinfo &si, u8 pong)
761{ 793{
762 ping_packet *pkt = new ping_packet; 794 ping_packet *pkt = new ping_packet;
763 795
764 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);
765 797
766 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si); 798 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si);
767
768 send_vpn_packet (pkt, si, IPTOS_LOWDELAY); 799 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
769 800
770 delete pkt; 801 delete pkt;
771} 802}
772 803
… …
787void 818void
788connection::send_auth_request (const sockinfo &si, bool initiate) 819connection::send_auth_request (const sockinfo &si, bool initiate)
789{ 820{
790 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);
791 822
792 rsachallenge chg; 823 generate_auth_data ();
793 rsa_cache.gen (pkt->id, chg);
794 rsa_encrypt (conf->rsa_key, chg, pkt->encr); 824 auth_encrypt (conf->rsa_key, snd_auth, pkt->encr);
795 825
796 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si); 826 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si);
797
798 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
799 828
800 delete pkt; 829 delete pkt;
801} 830}
802 831
803void 832void
804connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 833connection::send_auth_response (const sockinfo &si)
805{ 834{
806 auth_res_packet *pkt = new auth_res_packet (conf->id); 835 auth_res_packet *pkt = new auth_res_packet (conf->id);
807 836
808 pkt->id = id; 837 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof rcv_ecdh_b);
809 838 auth_hash (rcv_auth, rcv_ecdh_b, pkt->response.mac);
810 rsa_hash (id, chg, pkt->response);
811
812 pkt->hmac_set (octx);
813 839
814 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si); 840 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si);
815
816 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
817 842
818 delete pkt; 843 delete pkt;
819} 844}
820 845
821void 846void
822connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols) 847connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols)
823{ 848{
824 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s)", conf->nodename, 849 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s,p%02x)", conf->nodename,
825 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi); 850 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi,
851 conf->protocols);
826 852
827 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);
828 854
829 r->hmac_set (octx); 855 r->hmac_set (octx);
830 send_vpn_packet (r, si); 856 send_vpn_packet (r, si);
… …
833} 859}
834 860
835inline void 861inline void
836connection::establish_connection_cb (ev::timer &w, int revents) 862connection::establish_connection_cb (ev::timer &w, int revents)
837{ 863{
838 if (!ictx 864 if (!(ictx && octx)
839 && conf != THISNODE 865 && conf != THISNODE
840 && connectmode != conf_node::C_NEVER 866 && connectmode != conf_node::C_NEVER
841 && connectmode != conf_node::C_DISABLED 867 && connectmode != conf_node::C_DISABLED
842 && !w.is_active ()) 868 && !w.is_active ())
843 { 869 {
844 // 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
845 // 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.
846 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 ())
847 { 873 {
848 reset_connection (); 874 reset_connection ("no demand");
849 return; 875 return;
850 } 876 }
851 877
852 last_establish_attempt = ev_now (); 878 last_establish_attempt = ev_now ();
853 879
… …
855 ? (retry_cnt & 3) + 1 881 ? (retry_cnt & 3) + 1
856 : 1 << (retry_cnt >> 2)); 882 : 1 << (retry_cnt >> 2));
857 883
858 reset_si (); 884 reset_si ();
859 885
860 bool slow = si.prot & PROT_SLOW; 886 bool slow = (si.prot & PROT_SLOW) || (conf->low_power || THISNODE->low_power);
861 887
862 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf)) 888 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf))
863 { 889 {
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);
… …
875 901
876 slow = slow || (dsi.prot & PROT_SLOW); 902 slow = slow || (dsi.prot & PROT_SLOW);
877 903
878 if (dsi.valid () && auth_rate_limiter.can (dsi)) 904 if (dsi.valid () && auth_rate_limiter.can (dsi))
879 { 905 {
880 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))
881 send_auth_request (dsi, true); 910 send_auth_request (dsi, true);
882 else 911 else
883 send_ping (dsi, 0); 912 send_ping (dsi, 0);
884 } 913 }
885 } 914 }
886 915
887 retry_int *= slow ? 8. : 0.9; 916 retry_int *= slow ? 4. : 0.9;
888 917
889 if (retry_int < conf->max_retry) 918 if (retry_int < conf->max_retry)
890 retry_cnt++; 919 retry_cnt++;
891 else 920 else
892 retry_int = conf->max_retry; 921 retry_int = conf->max_retry;
… …
894 w.start (retry_int); 923 w.start (retry_int);
895 } 924 }
896} 925}
897 926
898void 927void
899connection::reset_connection () 928connection::reset_connection (const char *reason)
900{ 929{
901 if (ictx && octx) 930 if (ictx && octx)
902 { 931 {
903 slog (L_INFO, _("%s(%s): connection lost"), 932 slog (L_INFO, _("%s(%s): connection lost (%s)"),
904 conf->nodename, (const char *)si); 933 conf->nodename, (const char *)si, reason);
905 934
906 if (::conf.script_node_down) 935 if (::conf.script_node_down)
907 { 936 {
908 run_script_cb *cb = new run_script_cb; 937 run_script_cb *cb = new run_script_cb;
909 cb->set<connection, &connection::script_node_down> (this); 938 cb->set<connection, &connection::script_node_down> (this);
… …
911 } 940 }
912 } 941 }
913 942
914 delete ictx; ictx = 0; 943 delete ictx; ictx = 0;
915 delete octx; octx = 0; 944 delete octx; octx = 0;
916#if ENABLE_DNS
917 dnsv4_reset_connection ();
918#endif
919 945
920 si.host = 0; 946 si.host = 0;
947
948 have_snd_auth = false;
949 have_rcv_auth = false;
950 auth_expire = 0.;
921 951
922 last_activity = 0.; 952 last_activity = 0.;
923 //last_si_change = 0.; 953 //last_si_change = 0.;
924 retry_cnt = 0; 954 retry_cnt = 0;
925 955
… …
932connection::shutdown () 962connection::shutdown ()
933{ 963{
934 if (ictx && octx) 964 if (ictx && octx)
935 send_reset (si); 965 send_reset (si);
936 966
937 reset_connection (); 967 reset_connection ("shutdown");
938} 968}
939 969
940// poor-man's rekeying 970// poor-man's rekeying
941inline void 971inline void
942connection::rekey_cb (ev::timer &w, int revents) 972connection::rekey_cb (ev::timer &w, int revents)
943{ 973{
944 reset_connection (); 974 reset_connection ("rekeying");
945 establish_connection (); 975 establish_connection ();
946} 976}
947 977
948void 978void
949connection::send_data_packet (tap_packet *pkt) 979connection::send_data_packet (tap_packet *pkt)
… …
966 996
967void 997void
968connection::post_inject_queue () 998connection::post_inject_queue ()
969{ 999{
970 // 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)
971 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
972 establish_connection.stop (); 1002 establish_connection.stop ();
973 1003
974 establish_connection (); 1004 establish_connection ();
975} 1005}
976 1006
… …
984 data_queue.put (new tap_packet (*pkt)); 1014 data_queue.put (new tap_packet (*pkt));
985 post_inject_queue (); 1015 post_inject_queue ();
986 } 1016 }
987} 1017}
988 1018
1019void
989void connection::inject_vpn_packet (vpn_packet *pkt, int tos) 1020connection::inject_vpn_packet (vpn_packet *pkt, int tos)
990{ 1021{
991 if (ictx && octx) 1022 if (ictx && octx)
992 send_vpn_packet (pkt, si, tos); 1023 send_vpn_packet (pkt, si, tos);
993 else 1024 else
994 { 1025 {
… …
1000void 1031void
1001connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) 1032connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
1002{ 1033{
1003 last_activity = ev_now (); 1034 last_activity = ev_now ();
1004 1035
1005 slog (L_NOISE, "%s >> received packet type %d from %d to %d.", 1036 slog (L_NOISE, "%s >> received packet type %d from %d to %d.",
1006 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ()); 1037 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ());
1007 1038
1008 if (connectmode == conf_node::C_DISABLED) 1039 if (connectmode == conf_node::C_DISABLED)
1009 return; 1040 return;
1010 1041
… …
1020 { 1051 {
1021 if (auth_rate_limiter.can (rsi)) 1052 if (auth_rate_limiter.can (rsi))
1022 send_auth_request (rsi, true); 1053 send_auth_request (rsi, true);
1023 } 1054 }
1024 else 1055 else
1025 // we would love to change thre socket address here, but ping's aren't 1056 // we would love to change the socket address here, but ping's aren't
1026 // authenticated, so we best ignore it. 1057 // authenticated, so we best ignore it.
1027 send_ping (rsi, 1); // pong 1058 send_ping (rsi, 1); // pong
1028 1059
1029 break; 1060 break;
1030 1061
1031 case vpn_packet::PT_PONG: 1062 case vpn_packet::PT_PONG:
1032 slog (L_TRACE, "%s >> PT_PONG", conf->nodename); 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 ();
1033 break; 1068 break;
1034 1069
1035 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)
1036 { 1074 {
1037 reset_connection (); 1075 reset_connection ("remote reset");
1038 1076
1039 config_packet *p = (config_packet *) pkt; 1077 config_packet *p = (config_packet *) pkt;
1040 1078
1041 if (!p->chk_config ()) 1079 if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
1042 {
1043 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node."),
1044 conf->nodename, (const char *)rsi);
1045 connectmode = conf_node::C_DISABLED;
1046 }
1047 else if (connectmode == conf_node::C_ALWAYS)
1048 establish_connection (); 1080 establish_connection ();
1049 } 1081 }
1082
1050 break; 1083 break;
1051 1084
1052 case vpn_packet::PT_AUTH_REQ: 1085 case vpn_packet::PT_AUTH_REQ:
1053 if (auth_rate_limiter.can (rsi)) 1086 if (auth_rate_limiter.can (rsi))
1054 { 1087 {
1055 auth_req_packet *p = (auth_req_packet *) pkt; 1088 auth_req_packet *p = (auth_req_packet *)pkt;
1056 1089
1057 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s)", conf->nodename, p->initiate ? "initiate" : "reply"); 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);
1058 1093
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 }
1059 if (p->chk_config () 1099 else if (p->chk_config (conf, rsi))
1060 && (!strncmp (p->magic, MAGIC_OLD, 8) || !strncmp (p->magic, MAGIC, 8)))
1061 { 1100 {
1062 if (p->prot_minor != PROTOCOL_MINOR) 1101 if (p->prot_minor != PROTOCOL_MINOR)
1063 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."),
1064 conf->nodename, (const char *)rsi, 1103 conf->nodename, (const char *)rsi,
1065 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1104 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1066 1105
1067 if (p->initiate) 1106 if (p->initiate)
1107 {
1068 send_auth_request (rsi, false); 1108 send_auth_request (rsi, false);
1069 1109
1070 rsachallenge k; 1110 if (ictx && octx)
1111 reset_connection ("reconnect");
1112 }
1071 1113
1114 auth_data auth;
1115
1072 if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) 1116 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
1073 { 1117 {
1074 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?"),
1075 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));
1076 break;
1077 } 1120 }
1078 else 1121 else
1079 { 1122 {
1080 delete octx; 1123 bool chg = !have_rcv_auth || memcmp (&rcv_auth, &auth, sizeof auth);
1081 1124
1082 octx = new crypto_ctx (k, 1); 1125 rcv_auth = auth;
1083 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 1126 have_rcv_auth = true;
1084 1127
1128 send_auth_response (rsi);
1129
1130 if (chg)
1131 {
1085 conf->protocols = p->protocols; 1132 conf->protocols = p->protocols;
1086 features = p->features & config_packet::get_features (); 1133 features = p->features & config_packet::get_features ();
1087 1134
1088 send_auth_response (rsi, p->id, k);
1089
1090 connection_established (); 1135 connection_established (rsi);
1091
1092 break; 1136 }
1093 } 1137 }
1138
1139 break;
1094 } 1140 }
1095 else
1096 slog (L_WARN, _("%s(%s): protocol mismatch."),
1097 conf->nodename, (const char *)rsi);
1098 1141
1099 send_reset (rsi); 1142 send_reset (rsi);
1100 } 1143 }
1101 1144
1102 break; 1145 break;
… …
1105 { 1148 {
1106 auth_res_packet *p = (auth_res_packet *)pkt; 1149 auth_res_packet *p = (auth_res_packet *)pkt;
1107 1150
1108 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename); 1151 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
1109 1152
1110 if (p->chk_config ()) 1153 auth_mac local_mac;
1154 auth_hash (snd_auth, p->response.ecdh, local_mac);
1155
1156 if (memcmp (&p->response.mac, local_mac, sizeof local_mac))
1111 { 1157 {
1112 if (p->prot_minor != PROTOCOL_MINOR)
1113 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1114 conf->nodename, (const char *)rsi,
1115 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1116
1117 rsachallenge chg;
1118
1119 if (!rsa_cache.find (p->id, chg))
1120 {
1121 slog (L_ERR, _("%s(%s): unrequested auth response, ignoring."), 1158 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
1122 conf->nodename, (const char *)rsi); 1159 conf->nodename, (const char *)rsi);
1123 break;
1124 } 1160 }
1125 else 1161 else if (!have_snd_auth)
1126 { 1162 {
1127 crypto_ctx *cctx = new crypto_ctx (chg, 0); 1163 memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
1128 1164
1129 if (!p->hmac_chk (cctx)) 1165 have_snd_auth = true;
1130 {
1131 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
1132 "could be an attack, or just corruption or a synchronization error."),
1133 conf->nodename, (const char *)rsi);
1134 break;
1135 }
1136 else
1137 {
1138 rsaresponse h;
1139
1140 rsa_hash (p->id, chg, h);
1141
1142 if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
1143 {
1144 prot_minor = p->prot_minor;
1145
1146 delete ictx; ictx = cctx;
1147
1148 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
1149
1150 si = rsi;
1151 protocol = rsi.prot;
1152
1153 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
1154 conf->nodename, (const char *)rsi,
1155 is_direct ? "direct" : "forwarded",
1156 p->prot_major, p->prot_minor);
1157
1158 connection_established (); 1166 connection_established (rsi);
1159
1160 if (::conf.script_node_up)
1161 {
1162 run_script_cb *cb = new run_script_cb;
1163 cb->set<connection, &connection::script_node_up> (this);
1164 run_script_queued (cb, _("node-up command execution failed, continuing."));
1165 }
1166
1167 break;
1168 }
1169 else
1170 slog (L_ERR, _("%s(%s): sent and received challenge do not match."),
1171 conf->nodename, (const char *)rsi);
1172 }
1173
1174 delete cctx;
1175 }
1176 } 1167 }
1177 } 1168 }
1178
1179 send_reset (rsi);
1180 break; 1169 break;
1181 1170
1182 case vpn_packet::PT_DATA_COMPRESSED: 1171 case vpn_packet::PT_DATA_COMPRESSED:
1183#if !ENABLE_COMPRESSION 1172#if !ENABLE_COMPRESSION
1184 send_reset (rsi); 1173 send_reset (rsi);
… …
1190 if (ictx && octx) 1179 if (ictx && octx)
1191 { 1180 {
1192 vpndata_packet *p = (vpndata_packet *)pkt; 1181 vpndata_packet *p = (vpndata_packet *)pkt;
1193 1182
1194 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 {
1195 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"
1196 "could be an attack, or just corruption or a synchronization error."), 1199 "could be an attack, or just corruption or a synchronization error."),
1197 conf->nodename, (const char *)rsi); 1200 conf->nodename, (const char *)rsi);
1201 // reset
1202 }
1203 }
1198 else 1204 else
1199 { 1205 {
1200 u32 seqno; 1206 u32 seqno;
1201 tap_packet *d = p->unpack (this, seqno); 1207 tap_packet *d = p->unpack (this, seqno);
1202 int seqclass = iseqno.seqno_classify (seqno); 1208 int seqclass = iseqno.seqno_classify (seqno);
1209
1210 hmac_error = 0;
1203 1211
1204 if (seqclass == 0) // ok 1212 if (seqclass == 0) // ok
1205 { 1213 {
1206 vpn->tap->send (d); 1214 vpn->tap->send (d);
1207 1215
… …
1257 if (p->id > 0 && p->id <= vpn->conns.size ()) 1265 if (p->id > 0 && p->id <= vpn->conns.size ())
1258 { 1266 {
1259 connection *c = vpn->conns[p->id - 1]; 1267 connection *c = vpn->conns[p->id - 1];
1260 conf->protocols = p->protocols; 1268 conf->protocols = p->protocols;
1261 1269
1262 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s) [%d]", 1270 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s,p%02x) [%d]",
1263 conf->nodename, vpn->conns[p->id - 1]->conf->nodename, c->ictx && c->octx); 1271 conf->nodename, vpn->conns[p->id - 1]->conf->nodename,
1272 p->protocols,
1273 c->ictx && c->octx);
1264 1274
1265 if (c->ictx && c->octx) 1275 if (c->ictx && c->octx)
1266 { 1276 {
1267 // send connect_info packets to both sides, in case one is 1277 // send connect_info packets to both sides, in case one is
1268 // behind a nat firewall (or both ;) 1278 // behind a nat firewall (or both ;)
… …
1291 1301
1292 c->conf->protocols = p->protocols; 1302 c->conf->protocols = p->protocols;
1293 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));
1294 p->si.upgrade_protocol (protocol, c->conf); 1304 p->si.upgrade_protocol (protocol, c->conf);
1295 1305
1296 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s) [%d]", 1306 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s,protocols=%02x,protocol=%02x,upgradable=%02x) [%d]",
1307 conf->nodename,
1297 conf->nodename, vpn->conns[p->id - 1]->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),
1298 (const char *)p->si, !c->ictx && !c->octx); 1313 !c->ictx && !c->octx);
1299 1314
1300 const sockinfo &dsi = forward_si (p->si); 1315 const sockinfo &dsi = forward_si (p->si);
1301 1316
1302 if (dsi.valid ()) 1317 if (dsi.valid ())
1303 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);
1304 } 1323 }
1305 else 1324 else
1306 slog (L_WARN, 1325 slog (L_WARN,
1307 _("received authenticated connection request from unknown node #%d, config file mismatch?"), 1326 _("received authenticated connection request from unknown node #%d, config file mismatch?"),
1308 p->id); 1327 p->id);
… …
1317} 1336}
1318 1337
1319inline void 1338inline void
1320connection::keepalive_cb (ev::timer &w, int revents) 1339connection::keepalive_cb (ev::timer &w, int revents)
1321{ 1340{
1322 if (ev_now () >= last_activity + ::conf.keepalive + 15) 1341 ev_tstamp when = last_activity + ::conf.keepalive - ev::now ();
1342
1343 if (when >= 0)
1344 w.start (when);
1345 else if (when < -15)
1323 { 1346 {
1324 reset_connection (); 1347 reset_connection ("keepalive overdue");
1325 establish_connection (); 1348 establish_connection ();
1326 } 1349 }
1327 else if (ev_now () < last_activity + ::conf.keepalive)
1328 w.start (last_activity + ::conf.keepalive - ev::now ());
1329 else if (conf->connectmode != conf_node::C_ONDEMAND 1350 else if (conf->connectmode != conf_node::C_ONDEMAND
1330 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1351 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1331 { 1352 {
1353 w.start (3);
1332 send_ping (si); 1354 send_ping (si);
1333 w.start (3);
1334 } 1355 }
1335 else if (ev_now () < last_activity + ::conf.keepalive + 10) 1356 else if (when >= -10)
1336 // hold ondemand connections implicitly a few seconds longer 1357 // hold ondemand connections implicitly a few seconds longer
1337 // should delete octx, though, or something like that ;) 1358 // should delete octx, though, or something like that ;)
1338 w.start (last_activity + ::conf.keepalive + 10 - ev::now ()); 1359 w.start (when + 10);
1339 else 1360 else
1340 reset_connection (); 1361 reset_connection ("keepalive timeout");
1341} 1362}
1342 1363
1364void
1343void connection::send_connect_request (int id) 1365connection::send_connect_request (int id)
1344{ 1366{
1345 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);
1346 1368
1347 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s)", 1369 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s,p%02x)",
1348 conf->nodename, vpn->conns[id - 1]->conf->nodename); 1370 conf->nodename, vpn->conns[id - 1]->conf->nodename,
1371 THISNODE->protocols);
1349 p->hmac_set (octx); 1372 p->hmac_set (octx);
1350 send_vpn_packet (p, si); 1373 send_vpn_packet (p, si);
1351 1374
1352 delete p; 1375 delete p;
1353} 1376}
1354 1377
1378void
1355void connection::script_init_env (const char *ext) 1379connection::script_init_env (const char *ext)
1356{ 1380{
1357 char *env; 1381 char *env;
1358 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);
1359 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env); 1383 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env);
1360 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext, 1384 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext,
1361 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8, 1385 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8,
1362 conf->id & 0xff); putenv (env); 1386 conf->id & 0xff); putenv (env);
1363} 1387}
1364 1388
1389void
1365void connection::script_init_connect_env () 1390connection::script_init_connect_env ()
1366{ 1391{
1367 vpn->script_init_env (); 1392 vpn->script_init_env ();
1368 1393
1369 char *env; 1394 char *env;
1370 asprintf (&env, "DESTID=%d", conf->id); putenv (env); 1395 asprintf (&env, "DESTID=%d", conf->id); putenv (env);
… …
1435 establish_connection.set<connection, &connection::establish_connection_cb> (this); 1460 establish_connection.set<connection, &connection::establish_connection_cb> (this);
1436 1461
1437 last_establish_attempt = 0.; 1462 last_establish_attempt = 0.;
1438 octx = ictx = 0; 1463 octx = ictx = 0;
1439 1464
1440 if (!conf->protocols) // make sure some protocol is enabled
1441 conf->protocols = PROT_UDPv4;
1442
1443 connectmode = conf->connectmode; 1465 connectmode = conf->connectmode;
1444 1466
1445 // queue a dummy packet to force an initial connection attempt 1467 // queue a dummy packet to force an initial connection attempt
1446 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) 1468 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
1447 vpn_queue.put (new net_packet); 1469 vpn_queue.put (new net_packet);
1448 1470
1449 reset_connection (); 1471 reset_connection ("startup");
1450} 1472}
1451 1473
1452connection::~connection () 1474connection::~connection ()
1453{ 1475{
1454 shutdown (); 1476 shutdown ();
1455} 1477}
1456 1478
1479void
1457void connection_init () 1480connection_init ()
1458{ 1481{
1459 auth_rate_limiter.clear (); 1482 auth_rate_limiter.clear ();
1460 reset_rate_limiter.clear (); 1483 reset_rate_limiter.clear ();
1461} 1484}
1462 1485

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