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Comparing gvpe/src/connection.C (file contents):
Revision 1.101 by root, Wed Jul 17 16:40:57 2013 UTC vs.
Revision 1.113 by root, Thu Jan 29 00:21:39 2015 UTC

… …
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"
… …
48#include "hkdf.h" 56#include "hkdf.h"
49 57
50#include "netcompat.h" 58#include "netcompat.h"
51 59
52#define MAGIC "gvpe\xbd\xc6\xdb\x82" // 8 bytes of magic 60#define MAGIC "gvpe\xbd\xc6\xdb\x82" // 8 bytes of magic
53#define MAGIC "PORN\xbd\xc6\xdb\x82" // 8 bytes of magic//D
54 61
55#define ULTRA_FAST 1 62#define ULTRA_FAST 1
56#define HLOG 15 63#define HLOG 15
57#include "lzf/lzf.h" 64#include "lzf/lzf.h"
58#include "lzf/lzf_c.c" 65#include "lzf/lzf_c.c"
… …
120 { 127 {
121 u8 mac_key[MAC_KEYSIZE]; 128 u8 mac_key[MAC_KEYSIZE];
122 static const unsigned char mac_info[] = "gvpe mac key"; 129 static const unsigned char mac_info[] = "gvpe mac key";
123 130
124 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ()); 131 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
125 kdf.extract (auth2.rsa.ikm, sizeof (auth2.rsa.ikm));
126 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key)); 132 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key));
127 kdf.extract (s, sizeof (s)); 133 kdf.extract (s, sizeof (s));
128 kdf.extract_done (HKDF_PRF_HASH ()); 134 kdf.extract_done (HKDF_PRF_HASH ());
129 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info)); 135 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info));
130 136
131 HMAC_CTX_init (&hctx); 137 HMAC_CTX_init (&hctx);
132 require (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0)); 138 require101 (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0));
133 } 139 }
134 140
135 { 141 {
136 u8 cipher_key[CIPHER_KEYSIZE]; 142 u8 cipher_key[CIPHER_KEYSIZE];
137 static const unsigned char cipher_info[] = "gvpe cipher key"; 143 static const unsigned char cipher_info[] = "gvpe cipher key";
138 144
139 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ()); 145 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
140 kdf.extract (auth2.rsa.ikm, sizeof (auth2.rsa.ikm));
141 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key)); 146 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key));
142 kdf.extract (s, sizeof (s)); 147 kdf.extract (s, sizeof (s));
143 kdf.extract_done (HKDF_PRF_HASH ()); 148 kdf.extract_done (HKDF_PRF_HASH ());
144 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info)); 149 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info));
145 150
… …
180 185
181 return 1; 186 return 1;
182} 187}
183 188
184static void 189static void
185auth_hash (const auth_data &auth, auth_mac &mac) 190auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
186{ 191{
187 HMAC_CTX ctx; 192 hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt
188 193 kdf.extract (&auth.rsa, sizeof (auth.rsa));
189 HMAC_CTX_init (&ctx); 194 kdf.extract_done ();
190 require (HMAC_Init_ex (&ctx, auth.rsa.auth_key, sizeof (auth.rsa.auth_key), AUTH_DIGEST (), 0)); 195 kdf.expand (mac, sizeof mac, auth.ecdh, sizeof (auth.ecdh)); // use challenge ecdh b as info
191 require (HMAC_Update (&ctx, (const unsigned char *)&auth, sizeof auth));
192 require (HMAC_Final (&ctx, (unsigned char *)&mac, 0));
193 HMAC_CTX_cleanup (&ctx);
194} 196}
195 197
196void 198void
197connection::generate_auth_data () 199connection::generate_auth_data ()
198{ 200{
199 if (auth_expire < ev_now ()) 201 if (auth_expire < ev_now ())
200 { 202 {
201 // request data 203 // request data
202 rand_fill (snd_auth.rsa); 204 rand_fill (snd_auth.rsa);
203 curve25519_generate (snd_ecdh_a, snd_auth.ecdh); 205 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
204 auth_hash (snd_auth, snd_auth_mac);
205 206
206 // eventual response data 207 // eventual response data
207 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b); 208 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
208 } 209 }
209 210
… …
365 } 366 }
366} 367}
367 368
368///////////////////////////////////////////////////////////////////////////// 369/////////////////////////////////////////////////////////////////////////////
369 370
370unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE];
371
372void 371void
373hmac_packet::hmac_gen (crypto_ctx *ctx) 372hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
374{ 373{
375 unsigned int xlen;
376
377 HMAC_CTX *hctx = &ctx->hctx; 374 HMAC_CTX *hctx = &ctx->hctx;
378 375
379 require (HMAC_Init_ex (hctx, 0, 0, 0, 0)); 376 require101 (HMAC_Init_ex (hctx, 0, 0, 0, 0));
380 require (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), 377 require101 (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet)));
381 len - sizeof (hmac_packet)));
382 require (HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen)); 378 require101 (HMAC_Final (hctx, hmac_digest, 0));
383} 379}
384 380
385void 381void
386hmac_packet::hmac_set (crypto_ctx *ctx) 382hmac_packet::hmac_set (crypto_ctx *ctx)
387{ 383{
388 hmac_gen (ctx); 384 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
389 385 hmac_gen (ctx, hmac_digest);
390 memcpy (hmac, hmac_digest, HMACLENGTH); 386 memcpy (hmac, hmac_digest, HMACLENGTH);
391} 387}
392 388
393bool 389bool
394hmac_packet::hmac_chk (crypto_ctx *ctx) 390hmac_packet::hmac_chk (crypto_ctx *ctx)
395{ 391{
396 hmac_gen (ctx); 392 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
397 393 hmac_gen (ctx, hmac_digest);
398 return !memcmp (hmac, hmac_digest, HMACLENGTH); 394 return slow_memeq (hmac, hmac_digest, HMACLENGTH);
399} 395}
400 396
401void 397void
402vpn_packet::set_hdr (ptype type_, unsigned int dst) 398vpn_packet::set_hdr (ptype type_, unsigned int dst)
403{ 399{
… …
409 srcdst = ((src >> 8) << 4) | (dst >> 8); 405 srcdst = ((src >> 8) << 4) | (dst >> 8);
410 dst1 = dst; 406 dst1 = dst;
411} 407}
412 408
413#define MAXVPNDATA (MAX_MTU - 6 - 6) 409#define MAXVPNDATA (MAX_MTU - 6 - 6)
414#define DATAHDR (sizeof (u32) + RAND_SIZE)
415 410
416struct vpndata_packet : vpn_packet 411struct vpndata_packet : vpn_packet
417{ 412{
418 u8 data[MAXVPNDATA + DATAHDR]; // seqno 413 u32 ctr; // seqno
414 u8 data[MAXVPNDATA];
419 415
420 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno); 416 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
421 tap_packet *unpack (connection *conn, u32 &seqno); 417 tap_packet *unpack (connection *conn, u32 &seqno);
422 418
423private: 419private:
424 const u32 data_hdr_size () const 420 const u32 data_hdr_size () const
425 { 421 {
426 return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR; 422 // the distance from beginning of packet to data member
423 return data - at (0);
427 } 424 }
428}; 425};
426
427// expands packet counter (unlike seqno, in network byte order) to counter mode IV
428static unsigned char *
429expand_iv (u32 ctr)
430{
431 static u32 iv[IV_SIZE (CIPHER) / 4];
432
433 require (sizeof (iv) == 4 * 4);
434 require (IV_SIZE (CIPHER) % 4 == 0);
435
436 iv[0] =
437 iv[1] =
438 iv[2] = ctr;
439
440 // I would reuse ctr here to to avoid potential endianness issues,
441 // but it seems openssl wraps around. While this would be still ok,
442 // and I don't even know if its true, let's play safe and initialise
443 // to 0.
444 iv[3] = 0;
445
446 return (unsigned char *)iv;
447}
429 448
430void 449void
431vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno) 450vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno)
432{ 451{
433 EVP_CIPHER_CTX *cctx = &conn->octx->cctx; 452 EVP_CIPHER_CTX *cctx = &conn->octx->cctx;
… …
451 d[1] = cl; 470 d[1] = cl;
452 } 471 }
453 } 472 }
454#endif 473#endif
455 474
456 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 1)); 475 ctr = htonl (seqno);
457 476
458 struct { 477 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, expand_iv (ctr)));
459#if RAND_SIZE
460 u8 rnd[RAND_SIZE];
461#endif
462 u32 seqno;
463 } datahdr;
464
465 datahdr.seqno = ntohl (seqno);
466#if RAND_SIZE
467 require (RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE) >= 0);
468#endif
469 478
470 require (EVP_EncryptUpdate (cctx, 479 require (EVP_EncryptUpdate (cctx,
471 (unsigned char *) data + outl, &outl2, 480 (unsigned char *)data + outl, &outl2,
472 (unsigned char *) &datahdr, DATAHDR)); 481 (unsigned char *)d, l));
473 outl += outl2; 482 outl += outl2;
474 483
475 require (EVP_EncryptUpdate (cctx, 484 // it seems this is a nop for us, but we do it anyways
476 (unsigned char *) data + outl, &outl2, 485 require (EVP_EncryptFinal_ex (cctx, (unsigned char *)data + outl, &outl2));
477 (unsigned char *) d, l));
478 outl += outl2; 486 outl += outl2;
479 487
480 require (EVP_EncryptFinal_ex (cctx, (unsigned char *) data + outl, &outl2));
481 outl += outl2;
482
483 len = outl + data_hdr_size (); 488 len = data_hdr_size () + outl;
484 489
485 set_hdr (type, dst); 490 set_hdr (type, dst);
486 491
487 hmac_set (conn->octx); 492 hmac_set (conn->octx);
488} 493}
… …
492{ 497{
493 EVP_CIPHER_CTX *cctx = &conn->ictx->cctx; 498 EVP_CIPHER_CTX *cctx = &conn->ictx->cctx;
494 int outl = 0, outl2; 499 int outl = 0, outl2;
495 tap_packet *p = new tap_packet; 500 tap_packet *p = new tap_packet;
496 u8 *d; 501 u8 *d;
497 u32 l = len - data_hdr_size ();
498 502
499 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 0)); 503 seqno = ntohl (ctr);
504
505 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, expand_iv (ctr)));
500 506
501#if ENABLE_COMPRESSION 507#if ENABLE_COMPRESSION
502 u8 cdata[MAX_MTU]; 508 u8 cdata[MAX_MTU];
503 509
504 if (type == PT_DATA_COMPRESSED) 510 if (type == PT_DATA_COMPRESSED)
505 d = cdata; 511 d = cdata;
506 else 512 else
507#endif 513#endif
508 d = &(*p)[6 + 6] - DATAHDR; 514 d = &(*p)[6 + 6];
509
510 // we play do evil games with the struct layout atm.
511 // pending better solutions, we at least do some verification.
512 // this is fine, as we left ISO territory long ago.
513 require (DATAHDR <= 16);
514 require ((u8 *)(&p->len + 1) == &(*p)[0]);
515 515
516 // this can overwrite the len/dst/src fields 516 // this can overwrite the len/dst/src fields
517 require (EVP_DecryptUpdate (cctx, 517 require (EVP_DecryptUpdate (cctx,
518 d, &outl2, 518 d, &outl2,
519 (unsigned char *)&data, len - data_hdr_size ())); 519 (unsigned char *)&data, len - data_hdr_size ()));
520 outl += outl2; 520 outl += outl2;
521 521
522 // it seems this is a nop for us, but we do it anyways
522 require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2)); 523 require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2));
523 outl += outl2; 524 outl += outl2;
524 525
525 seqno = ntohl (*(u32 *)(d + RAND_SIZE));
526
527 id2mac (dst () ? dst() : THISNODE->id, p->dst); 526 id2mac (dst () ? dst() : THISNODE->id, p->dst);
528 id2mac (src (), p->src); 527 id2mac (src (), p->src);
529 528
530#if ENABLE_COMPRESSION 529#if ENABLE_COMPRESSION
531 if (type == PT_DATA_COMPRESSED) 530 if (type == PT_DATA_COMPRESSED)
532 { 531 {
533 u32 cl = (d[DATAHDR] << 8) | d[DATAHDR + 1]; 532 u32 cl = (d[0] << 8) | d[1];
534 533
535 p->len = lzf_decompress (d + DATAHDR + 2, cl < MAX_MTU ? cl : 0, 534 p->len = lzf_decompress (d + 2, cl < MAX_MTU - 2 ? cl : 0,
536 &(*p)[6 + 6], MAX_MTU) 535 &(*p)[6 + 6], MAX_MTU)
537 + 6 + 6; 536 + 6 + 6;
538 } 537 }
539 else 538 else
540 p->len = outl + (6 + 6 - DATAHDR); 539 p->len = outl + (6 + 6);
541#endif 540#endif
542 541
543 return p; 542 return p;
544} 543}
545 544
… …
552 } 551 }
553}; 552};
554 553
555struct config_packet : vpn_packet 554struct config_packet : vpn_packet
556{ 555{
556 u8 serial[SERIAL_SIZE];
557 u8 prot_major, prot_minor, randsize; 557 u8 prot_major, prot_minor, randsize;
558 u8 flags, features, pad6, pad7, pad8; 558 u8 flags, features, pad6, pad7, pad8;
559 u32 cipher_nid, mac_nid, auth_nid; 559 u32 cipher_nid, mac_nid, auth_nid;
560 560
561 void setup (ptype type, int dst); 561 void setup (ptype type, int dst);
562 bool chk_config () const; 562 bool chk_config (const conf_node *conf, const sockinfo &rsi) const;
563 563
564 static u8 get_features () 564 static u8 get_features ()
565 { 565 {
566 u8 f = 0; 566 u8 f = 0;
567#if ENABLE_COMPRESSION 567#if ENABLE_COMPRESSION
… …
580void 580void
581config_packet::setup (ptype type, int dst) 581config_packet::setup (ptype type, int dst)
582{ 582{
583 prot_major = PROTOCOL_MAJOR; 583 prot_major = PROTOCOL_MAJOR;
584 prot_minor = PROTOCOL_MINOR; 584 prot_minor = PROTOCOL_MINOR;
585 randsize = RAND_SIZE;
586 flags = 0; 585 flags = 0;
587 features = get_features (); 586 features = get_features ();
587
588 strncpy ((char *)serial, conf.serial, sizeof (serial));
588 589
589 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ())); 590 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
590 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ())); 591 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ()));
591 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ())); 592 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ()));
592 593
593 len = sizeof (*this) - sizeof (net_packet); 594 len = sizeof (*this) - sizeof (net_packet);
594 set_hdr (type, dst); 595 set_hdr (type, dst);
595} 596}
596 597
597bool 598bool
598config_packet::chk_config () const 599config_packet::chk_config (const conf_node *conf, const sockinfo &rsi) const
599{ 600{
600 if (prot_major != PROTOCOL_MAJOR) 601 if (prot_major != PROTOCOL_MAJOR)
601 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)"),
602 else if (randsize != RAND_SIZE) 603 conf->nodename, (const char *)rsi, prot_major, PROTOCOL_MAJOR);
603 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE);
604 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER ()))) 604 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER ())))
605 slog (L_WARN, _("cipher algo mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER ())); 605 slog (L_WARN, _("%s(%s): cipher algo mismatch (remote %x <=> local %x)"),
606 conf->nodename, (const char *)rsi, ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER ()));
606 else if (mac_nid != htonl (EVP_MD_type (MAC_DIGEST ()))) 607 else if (mac_nid != htonl (EVP_MD_type (MAC_DIGEST ())))
607 slog (L_WARN, _("mac algo mismatch (remote %x <=> local %x)"), ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ())); 608 slog (L_WARN, _("%s(%s): mac algo mismatch (remote %x <=> local %x)"),
609 conf->nodename, (const char *)rsi, ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ()));
608 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ()))) 610 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ())))
609 slog (L_WARN, _("auth algo mismatch (remote %x <=> local %x)"), ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ())); 611 slog (L_WARN, _("%s(%s): auth algo mismatch (remote %x <=> local %x)"),
612 conf->nodename, (const char *)rsi, ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ()));
610 else 613 else
614 {
615 int cmp = memcmp (serial, ::conf.serial, sizeof (serial));
616
617 if (cmp > 0)
618 slog (L_WARN, _("%s(%s): remote serial newer than local serial - outdated config?"),
619 conf->nodename, (const char *)rsi);
620 else if (cmp == 0)
611 return true; 621 return true;
622 }
612 623
613 return false; 624 return false;
614} 625}
615 626
616struct auth_req_packet : config_packet // UNPROTECTED 627struct auth_req_packet : config_packet // UNPROTECTED
… …
630 641
631 len = sizeof (*this) - sizeof (net_packet); 642 len = sizeof (*this) - sizeof (net_packet);
632 } 643 }
633}; 644};
634 645
635struct auth_res_packet : config_packet // UNPROTECTED 646struct auth_res_packet : vpn_packet // UNPROTECTED
636{ 647{
637 auth_response response; 648 auth_response response;
638 649
639 auth_res_packet (int dst) 650 auth_res_packet (int dst)
640 { 651 {
641 config_packet::setup (PT_AUTH_RES, dst); 652 set_hdr (PT_AUTH_RES, dst);
642 653
643 len = sizeof (*this) - sizeof (net_packet); 654 len = sizeof (*this) - sizeof (net_packet);
644 } 655 }
645}; 656};
646 657
… …
686 si = rsi; 697 si = rsi;
687 protocol = rsi.prot; 698 protocol = rsi.prot;
688 699
689 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."), 700 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
690 conf->nodename, (const char *)rsi, 701 conf->nodename, (const char *)rsi,
691 is_direct ? "direct" : "forwarded", 702 vpn->can_direct (THISNODE, conf) ? "direct" : "forwarded",
692 PROTOCOL_MAJOR, prot_minor); 703 PROTOCOL_MAJOR, prot_minor);
693 704
694 if (::conf.script_node_up) 705 if (::conf.script_node_up)
695 { 706 {
696 run_script_cb *cb = new run_script_cb; 707 run_script_cb *cb = new run_script_cb;
… …
702 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff); 713 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff);
703 714
704 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1); 715 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1);
705 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff; 716 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff;
706 717
707 if (ictx && octx)
708 {
709 // make sure rekeying timeouts are slightly asymmetric 718 // make sure rekeying timeouts are slightly asymmetric
710 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0); 719 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
711 rekey.start (rekey_interval, rekey_interval); 720 rekey.start (rekey_interval, rekey_interval);
712 721
722 hmac_error = 0.;
723
713 keepalive.start (::conf.keepalive); 724 keepalive.start (::conf.keepalive);
714 725
715 // send queued packets 726 // send queued packets
716 if (ictx && octx)
717 {
718 while (tap_packet *p = (tap_packet *)data_queue.get ()) 727 while (tap_packet *p = (tap_packet *)data_queue.get ())
719 { 728 {
720 if (p->len) send_data_packet (p); 729 if (p->len) send_data_packet (p);
721 delete p; 730 delete p;
722 } 731 }
723 732
724 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) 733 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
725 { 734 {
726 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); 735 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
727 delete p; 736 delete p;
728 } 737 }
729 }
730 738
731 vpn->connection_established (this); 739 vpn->connection_established (this);
732 }
733#if 0
734 else
735 {
736 retry_cnt = 0;
737 establish_connection.start (5);
738 keepalive.stop ();
739 rekey.stop ();
740 }
741#endif
742} 740}
743 741
744void 742void
745connection::reset_si () 743connection::reset_si ()
746{ 744{
… …
751 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename); 749 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename);
752 protocol = 0; 750 protocol = 0;
753 } 751 }
754 752
755 si.set (conf, protocol); 753 si.set (conf, protocol);
756
757 is_direct = si.valid ();
758} 754}
759 755
760// ensure sockinfo is valid, forward if necessary 756// ensure sockinfo is valid, forward if necessary
761const sockinfo & 757const sockinfo &
762connection::forward_si (const sockinfo &si) const 758connection::forward_si (const sockinfo &si) const
… …
781 777
782void 778void
783connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) 779connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
784{ 780{
785 if (!vpn->send_vpn_packet (pkt, si, tos)) 781 if (!vpn->send_vpn_packet (pkt, si, tos))
786 reset_connection (); 782 reset_connection ("packet send error");
787} 783}
788 784
789void 785void
790connection::send_ping (const sockinfo &si, u8 pong) 786connection::send_ping (const sockinfo &si, u8 pong)
791{ 787{
… …
830void 826void
831connection::send_auth_response (const sockinfo &si) 827connection::send_auth_response (const sockinfo &si)
832{ 828{
833 auth_res_packet *pkt = new auth_res_packet (conf->id); 829 auth_res_packet *pkt = new auth_res_packet (conf->id);
834 830
835 auth_hash (rcv_auth, pkt->response.mac);
836 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof (rcv_ecdh_b)); 831 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof rcv_ecdh_b);
832 auth_hash (rcv_auth, rcv_ecdh_b, pkt->response.mac);
837 833
838 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si); 834 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si);
839 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly 835 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly
840 836
841 delete pkt; 837 delete pkt;
… …
867 { 863 {
868 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection 864 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection
869 // and stop trying. should probably be handled by a per-connection expire handler. 865 // and stop trying. should probably be handled by a per-connection expire handler.
870 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ()) 866 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ())
871 { 867 {
872 reset_connection (); 868 reset_connection ("no demand");
873 return; 869 return;
874 } 870 }
875 871
876 last_establish_attempt = ev_now (); 872 last_establish_attempt = ev_now ();
877 873
… …
879 ? (retry_cnt & 3) + 1 875 ? (retry_cnt & 3) + 1
880 : 1 << (retry_cnt >> 2)); 876 : 1 << (retry_cnt >> 2));
881 877
882 reset_si (); 878 reset_si ();
883 879
884 bool slow = si.prot & PROT_SLOW; 880 bool slow = (si.prot & PROT_SLOW) || (conf->low_power || THISNODE->low_power);
885 881
886 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf)) 882 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf))
887 { 883 {
888 /*TODO*/ /* start the timer so we don't recurse endlessly */ 884 /*TODO*/ /* start the timer so we don't recurse endlessly */
889 w.start (1); 885 w.start (1);
… …
899 895
900 slow = slow || (dsi.prot & PROT_SLOW); 896 slow = slow || (dsi.prot & PROT_SLOW);
901 897
902 if (dsi.valid () && auth_rate_limiter.can (dsi)) 898 if (dsi.valid () && auth_rate_limiter.can (dsi))
903 { 899 {
904 if (retry_cnt < 4) 900 // use ping after the first few retries
901 // TODO: on rekeys, the other node might not interpret ping correctly,
902 // TODO: as it will still have a valid connection
903 if (retry_cnt < 4 && (!conf->low_power || THISNODE->low_power))
905 send_auth_request (dsi, true); 904 send_auth_request (dsi, true);
906 else 905 else
907 send_ping (dsi, 0); 906 send_ping (dsi, 0);
908 } 907 }
909 } 908 }
910 909
911 retry_int *= slow ? 8. : 0.9; 910 retry_int *= slow ? 4. : 0.9;
912 911
913 if (retry_int < conf->max_retry) 912 if (retry_int < conf->max_retry)
914 retry_cnt++; 913 retry_cnt++;
915 else 914 else
916 retry_int = conf->max_retry; 915 retry_int = conf->max_retry;
… …
918 w.start (retry_int); 917 w.start (retry_int);
919 } 918 }
920} 919}
921 920
922void 921void
923connection::reset_connection () 922connection::reset_connection (const char *reason)
924{ 923{
925 if (ictx && octx) 924 if (ictx && octx)
926 { 925 {
927 slog (L_INFO, _("%s(%s): connection lost"), 926 slog (L_INFO, _("%s(%s): connection lost (%s)"),
928 conf->nodename, (const char *)si); 927 conf->nodename, (const char *)si, reason);
929 928
930 if (::conf.script_node_down) 929 if (::conf.script_node_down)
931 { 930 {
932 run_script_cb *cb = new run_script_cb; 931 run_script_cb *cb = new run_script_cb;
933 cb->set<connection, &connection::script_node_down> (this); 932 cb->set<connection, &connection::script_node_down> (this);
… …
957connection::shutdown () 956connection::shutdown ()
958{ 957{
959 if (ictx && octx) 958 if (ictx && octx)
960 send_reset (si); 959 send_reset (si);
961 960
962 reset_connection (); 961 reset_connection ("shutdown");
963} 962}
964 963
965// poor-man's rekeying 964// poor-man's rekeying
966inline void 965inline void
967connection::rekey_cb (ev::timer &w, int revents) 966connection::rekey_cb (ev::timer &w, int revents)
968{ 967{
969 reset_connection (); 968 reset_connection ("rekeying");
970 establish_connection (); 969 establish_connection ();
971} 970}
972 971
973void 972void
974connection::send_data_packet (tap_packet *pkt) 973connection::send_data_packet (tap_packet *pkt)
… …
991 990
992void 991void
993connection::post_inject_queue () 992connection::post_inject_queue ()
994{ 993{
995 // force a connection every now and when when packets are sent (max 1/s) 994 // force a connection every now and when when packets are sent (max 1/s)
996 if (ev_now () - last_establish_attempt >= 0.95) // arbitrary 995 if (ev_now () - last_establish_attempt >= (conf->low_power || THISNODE->low_power ? 2.95 : 0.95)) // arbitrary
997 establish_connection.stop (); 996 establish_connection.stop ();
998 997
999 establish_connection (); 998 establish_connection ();
1000} 999}
1001 1000
… …
1061 // about our desire for communication. 1060 // about our desire for communication.
1062 establish_connection (); 1061 establish_connection ();
1063 break; 1062 break;
1064 1063
1065 case vpn_packet::PT_RESET: 1064 case vpn_packet::PT_RESET:
1065 slog (L_TRACE, "%s >> PT_RESET", conf->nodename);
1066
1067 if (ictx && octx)
1066 { 1068 {
1067 reset_connection (); 1069 reset_connection ("remote reset");
1068 1070
1069 config_packet *p = (config_packet *) pkt; 1071 config_packet *p = (config_packet *) pkt;
1070 1072
1071 if (!p->chk_config ()) 1073 if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
1072 {
1073 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node."),
1074 conf->nodename, (const char *)rsi);
1075 connectmode = conf_node::C_DISABLED;
1076 }
1077 else if (connectmode == conf_node::C_ALWAYS)
1078 establish_connection (); 1074 establish_connection ();
1079 } 1075 }
1076
1080 break; 1077 break;
1081 1078
1082 case vpn_packet::PT_AUTH_REQ: 1079 case vpn_packet::PT_AUTH_REQ:
1083 if (auth_rate_limiter.can (rsi)) 1080 if (auth_rate_limiter.can (rsi))
1084 { 1081 {
… …
1086 1083
1087 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)", 1084 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)",
1088 conf->nodename, p->initiate ? "initiate" : "reply", 1085 conf->nodename, p->initiate ? "initiate" : "reply",
1089 p->protocols, p->features); 1086 p->protocols, p->features);
1090 1087
1091 if (p->chk_config () && !memcmp (p->magic, MAGIC, 8)) 1088 if (memcmp (p->magic, MAGIC, 8))
1089 {
1090 slog (L_WARN, _("%s(%s): protocol magic mismatch - stray packet?"),
1091 conf->nodename, (const char *)rsi);
1092 }
1093 else if (p->chk_config (conf, rsi))
1092 { 1094 {
1093 if (p->prot_minor != PROTOCOL_MINOR) 1095 if (p->prot_minor != PROTOCOL_MINOR)
1094 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), 1096 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1095 conf->nodename, (const char *)rsi, 1097 conf->nodename, (const char *)rsi,
1096 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1098 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1097 1099
1098 if (p->initiate) 1100 if (p->initiate)
1101 {
1099 send_auth_request (rsi, false); 1102 send_auth_request (rsi, false);
1103
1104 if (ictx && octx)
1105 reset_connection ("reconnect");
1106 }
1100 1107
1101 auth_data auth; 1108 auth_data auth;
1102 1109
1103 if (!auth_decrypt (::conf.rsa_key, p->encr, auth)) 1110 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
1104 { 1111 {
1105 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), 1112 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
1106 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0)); 1113 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
1107 } 1114 }
1108 else 1115 else
1109 { 1116 {
1110 bool chg = !have_rcv_auth || memcmp (&rcv_auth, &auth, sizeof auth); 1117 bool chg = !have_rcv_auth || !slow_memeq (&rcv_auth, &auth, sizeof auth);
1111 1118
1112 rcv_auth = auth; 1119 rcv_auth = auth;
1113 have_rcv_auth = true; 1120 have_rcv_auth = true;
1114 1121
1115 send_auth_response (rsi); 1122 send_auth_response (rsi);
… …
1123 } 1130 }
1124 } 1131 }
1125 1132
1126 break; 1133 break;
1127 } 1134 }
1128 else
1129 slog (L_WARN, _("%s(%s): protocol mismatch."),
1130 conf->nodename, (const char *)rsi);
1131 1135
1132 send_reset (rsi); 1136 send_reset (rsi);
1133 } 1137 }
1134 1138
1135 break; 1139 break;
… …
1138 { 1142 {
1139 auth_res_packet *p = (auth_res_packet *)pkt; 1143 auth_res_packet *p = (auth_res_packet *)pkt;
1140 1144
1141 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename); 1145 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
1142 1146
1143 if (p->chk_config ()) 1147 auth_mac local_mac;
1148 auth_hash (snd_auth, p->response.ecdh, local_mac);
1149
1150 if (!slow_memeq (&p->response.mac, local_mac, sizeof local_mac))
1144 { 1151 {
1145 if (memcmp (&p->response.mac, snd_auth_mac, sizeof (snd_auth_mac)))
1146 {
1147 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."), 1152 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
1148 conf->nodename, (const char *)rsi); 1153 conf->nodename, (const char *)rsi);
1149 } 1154 }
1150 else if (!have_snd_auth) 1155 else if (!have_snd_auth)
1151 { 1156 {
1152 if (p->prot_minor != PROTOCOL_MINOR)
1153 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1154 conf->nodename, (const char *)rsi,
1155 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1156
1157 prot_minor = p->prot_minor;
1158 memcpy (snd_ecdh_b, p->response.ecdh, sizeof (snd_ecdh_b)); 1157 memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
1159 1158
1160 have_snd_auth = true; 1159 have_snd_auth = true;
1161 connection_established (rsi); 1160 connection_established (rsi);
1162 }
1163
1164 break;
1165 } 1161 }
1166 } 1162 }
1167
1168 send_reset (rsi);
1169 break; 1163 break;
1170 1164
1171 case vpn_packet::PT_DATA_COMPRESSED: 1165 case vpn_packet::PT_DATA_COMPRESSED:
1172#if !ENABLE_COMPRESSION 1166#if !ENABLE_COMPRESSION
1173 send_reset (rsi); 1167 send_reset (rsi);
… …
1179 if (ictx && octx) 1173 if (ictx && octx)
1180 { 1174 {
1181 vpndata_packet *p = (vpndata_packet *)pkt; 1175 vpndata_packet *p = (vpndata_packet *)pkt;
1182 1176
1183 if (!p->hmac_chk (ictx)) 1177 if (!p->hmac_chk (ictx))
1178 {
1179 // rekeying often creates temporary hmac auth floods
1180 // we assume they don't take longer than a few seconds normally,
1181 // and suppress messages and resets during that time.
1182 //TODO: should be done per source address
1183 if (!hmac_error)
1184 {
1185 hmac_error = ev_now () + 3;
1186 break;
1187 }
1188 else if (hmac_error >= ev_now ())
1189 break; // silently suppress
1190 else
1191 {
1184 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" 1192 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
1185 "could be an attack, or just corruption or a synchronization error."), 1193 "could be an attack, or just corruption or a synchronization error."),
1186 conf->nodename, (const char *)rsi); 1194 conf->nodename, (const char *)rsi);
1195 // reset
1196 }
1197 }
1187 else 1198 else
1188 { 1199 {
1189 u32 seqno; 1200 u32 seqno;
1190 tap_packet *d = p->unpack (this, seqno); 1201 tap_packet *d = p->unpack (this, seqno);
1191 int seqclass = iseqno.seqno_classify (seqno); 1202 int seqclass = iseqno.seqno_classify (seqno);
1203
1204 hmac_error = 0;
1192 1205
1193 if (seqclass == 0) // ok 1206 if (seqclass == 0) // ok
1194 { 1207 {
1195 vpn->tap->send (d); 1208 vpn->tap->send (d);
1196 1209
… …
1323 1336
1324 if (when >= 0) 1337 if (when >= 0)
1325 w.start (when); 1338 w.start (when);
1326 else if (when < -15) 1339 else if (when < -15)
1327 { 1340 {
1328 reset_connection (); 1341 reset_connection ("keepalive overdue");
1329 establish_connection (); 1342 establish_connection ();
1330 } 1343 }
1331 else if (conf->connectmode != conf_node::C_ONDEMAND 1344 else if (conf->connectmode != conf_node::C_ONDEMAND
1332 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1345 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1333 { 1346 {
… …
1337 else if (when >= -10) 1350 else if (when >= -10)
1338 // hold ondemand connections implicitly a few seconds longer 1351 // hold ondemand connections implicitly a few seconds longer
1339 // should delete octx, though, or something like that ;) 1352 // should delete octx, though, or something like that ;)
1340 w.start (when + 10); 1353 w.start (when + 10);
1341 else 1354 else
1342 reset_connection (); 1355 reset_connection ("keepalive timeout");
1343} 1356}
1344 1357
1345void 1358void
1346connection::send_connect_request (int id) 1359connection::send_connect_request (int id)
1347{ 1360{
… …
1447 1460
1448 // queue a dummy packet to force an initial connection attempt 1461 // queue a dummy packet to force an initial connection attempt
1449 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) 1462 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
1450 vpn_queue.put (new net_packet); 1463 vpn_queue.put (new net_packet);
1451 1464
1452 reset_connection (); 1465 reset_connection ("startup");
1453} 1466}
1454 1467
1455connection::~connection () 1468connection::~connection ()
1456{ 1469{
1457 shutdown (); 1470 shutdown ();

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